A while back I rescued a M-1914 4" Erfurt (1918 date-marked) as a nice 9MM shooter.
Why a 'shooter'?
The nickel finish would explain that

It's a numbers-matching pistol (# 3195 t), with the exception of the locking bolt and the sear.
The saddest part?
The machined notch at the front of the receiver, as in 'front sight', etc.

Anyway, I'm getting tired of the gun's lack of a hold-open latch and spring.
Every time I field-strip the gun and look at that empty cavity, I remind myself to get the assembly and spring and install it.
If you knowledgeable folks would be so kind,
1) Where would you recommend I buy the hold-open mechanism and spring,
-and-
2) My books tell me it's a pretty easy installation. Is it?
Thanks for your help,
Don