And I thought that scoping a Luger was silly...........just kidding....
something that allows me a few more years of semi, almost respectable shooting skill always has my attention.
As nice and easy as it looks, mounting an optical sight(usually a scope in most renditions) will try your patience as to functionality. More barrel weight/mass, more weight/mass on barrel, influences the function of the Luger as we all know. We all have seen the 16" barrels with the forearm on said barrel; sold with scope mount or without, and can be kinda the berries to function, and yet keep the pistol together.
The top of the Luger can be a difficult place for adjustable sights, lost enough of them to have a basic respect for toggle speed environments during operation. That speed resides in the barrel too.
Open red dots are can be made pretty light, might be a candidate if they can handle the movement(gaff). Tube red dots as nice as they are, are heavier.
The old German optic sights(mini scope) on an Arty has some issues in my own opinion, might be doable for those that hope for such....not sure it will be easy.
There were folks here at one time that used Arty Lugers(Lonnie Z.) with red dots, went thru a lot of red dots before he found one that could handle the cycle of the 9mm artillery.......he used to shoot coyotes out of his garden as I recall.
I am blessed with a left master eye that has the oldest cataract. So the old time picture of a carbine with a scope and mount was kinda a compromise for me. It used the large flat behind the sideplate for a removeable mount. In my own way, I bonded a similar mounting system that has two precision pins so and securing mechanism that the scope/mount can be removed from the pistol. The scope or optics of the day sits to the left of the toggle, and up a ways for working the toggle during charging. I have not experimented with a stock on the pistol, only has a 12" narrow tapered(light) barrel. As a pistol, the optics will allow preciseness to placing rounds on a target at longer than semi normal pistol ranges.
Hope someday a professional pistol optic system will come out for a Luger, it will take some R&D............and some patience in operation as well as time at the machines to make something worthwhile. Has no interest to the collector, but us shooters are here too albeit in smaller numbers every year.
I think the barrel mounted optic will work, but lightness will be an asset. Guess one does have the 45acp slug weight working on your side though...........
FWIW