Help me ID this home build Luger carbine 1920 patter?
 

Dont know if this is the right place to post but i think at its base its a commercial?

So I acquired the other day a home build 1920 pattern(?) Luger carbine and just had a few questions and to see what you guys thought.

My determination of it being a "home build" is the serial #82091, the forestock extension is soldered on, the rear of the toggle still has a sight on it, and there is no helper spring in the forestock or forward barrel lug for the helper.

now that being said im not really sure what this was to begin with. I received it with zero internals and polished out. It had the complete bolt number match 91 and toggle marked DWM w/ crown over the "N" and matching number on the rear toggle 91, the forestock w/ zero markings, grips marked GSX and the complete serial #, and the trigger side plate with matching number 91. All the internals (and I switched the side plate and safety side grip) came out of my 41 byf P08. The unit is chambered in 9mm and not 30 luger and there is an "A" stamp at the lug under the barrel and a "D" stamp at the rear of the receiver after the rails.

Any thoughts or suggestions and any sources for the Carbine style rear slider sight (im thinking thats going to be the hardest piece to come by) as I do want to complete the gun

https://s20.postimg.org/6ln7wstn1/20170901_125723.jpg

https://s20.postimg.org/sam40nvv1/20170901_125629.jpg

https://s20.postimg.org/a6j3g0y6l/20170901_125704.jpg

https://s20.postimg.org/c5zp7fsi5/20170901_130233.jpg

https://s20.postimg.org/wen2t5rt9/20170901_125756.jpg

https://s20.postimg.org/ozxr0s5xp/20170901_125803.jpg

https://s20.postimg.org/485a5sf7x/20170901_132502.jpg

https://s20.postimg.org/rnrsovoct/20170901_133006.jpg

https://s20.postimg.org/ouyl4uo0d/20170901_133402.jpg

Adding pics would really help!

John, NICE! At first I thought it might be a John Martz conversion..The bolt has a lazy Crown N so at least it's commercial.
Why did you change out the rear toggle and sideplate?

The left grip is fully checkered and the right comes with a Swiss border?

Great project gun. If it were mine I would try to completely assembly and rust blue this carbine as much for the bragging rights as the prestige of ownership.
I do not believe that the 9 mm carbines need a fore stock spring assist for full battery closure.

Thanks for some info guys.

The rear toggle is how I received it and I changed out the side plate just because it seemed to have a little more throw when the trigger was pulled and seemed to work a bit better. The trigger bar or sear or whatever the piece is that releases the firing pin was a bit sticky at first, though after i did some clean up im sure the original side plate will function just fine. The full checkered grip is off the p08 as well. The original grip would not fit correctly with the safety lever attached and I was not going to fit the grip to that safety as its going back to its home gun. Im going to get all the parts to make it function and throw all my numbers matching parts back on my byf p08.

Not needing the helper makes sense the gun did function when I shot it a few hours ago (and with a pretty standard load nothing hot, as I though I might need). Now to strip it all down again and acquire the parts. If anyone has good sources for parts let me know please and if anyone has any more info on it that too would be great.

Im assuming it was a blue gun originally just polished out correct?

Are you planning to use it with a stock or not? It can still be a pistol as it is or it could be a carbine with the stock as long as the barrel is 16". Its an interesting piece and looks like very nice work to me. A polished blue finish would be very nice on it.

its 11" so no legal use of stock where I am at though I will obtain one for "display only" purposes.
is there any way to tell if this is a John Martz conversion?

Neither does a .30 cal if done correctly; the 1902 carbines used the leaf spring which made closure problematic-solved by adding the "booster" spring. The 1920 type has a coil spring.:thumbup:

Calling it a "fake" is a little harsh, a "fake" to me is intended to deceive someone- this 1920 style is some guy's build of a 1920 type carbine. Perhaps some part of it is even original. JMHO.

the person selling it (actually we traded) was listing it as a 1902 carbine although I must say he knew nothing of nothing and I knew from the add it was not what he had listed it as. thats where fake came from - I will edit the post

Can you assemble a no-stamp SBR for 'display' purposes? I think I would not.

Oh it will not be assembled ever - that would not be legal

You could- with one of the "non-guns", but not with this :thumbup:one.

What a great project you have undertaken. It looks like some very nice work has already been done, and as you stated, it functions correctly. That is a real plus, in my way of thinking. This can turn out to be a real head turner at the range, and a source of great pride for you when finished. Congrats.

Thank you, I am very excited to finish, my only concern is finding a rear sight - if anyone sees an appropriate rear sight please let me know

The forearm extention and barrel with carbine rear sight base appear to be the type that JVM used. The only ways to tell for sure if john has anything to do with it, is the nature of the non-finsh (does it match his 'satin white ?), his initial JVM on the toggle or his MSTR (Martz Safety Toggle Release0 modification. TH

If it is a Martz gun there will be a JVM in an oval stamp somewhere on the gun...I have one that only has this mark on the frame under the side plate.

couldn't locate such a marking. Guess its just a random build