Greetings from Finland, I like building airguns as a hobby and have built many from scratch. Lately I have been making drawings for Walther LG200/300. The idea is to build the 16 or 21 Joule version of LG200 for general target shooting use, maybe casual FT training. I have good overall knowledge of these guns but missing some critically important details, most of the dimension I think are close enough but it is uncertain if original walther parts will fit. Almost all dimensions were derived from walther parts diagrams and reading online Airgun Accuracy I have ordered a 180x60x25 mm aluminium brick for the frame of the gun, it should be here friday, but I will not start machining it until the 3d model is verified. Dimensions I think are correct -Frame length and width and hole positions -Pellet pusher dia 6 mm. -barrel mounting hole 12 mm. Some of the dimensions I am unsure of are: -Exaxt barrel to air cylinder distance (center to center) -Depth of valve seat surface (I will use flat type ptfe valve seal) -Regulator lip length and offset from center (part that pushes against valve seal and how far it is from regulator centerline). Regulator is important to get right if I ever want to use the original part or get lazy in the process and decide to buy it. I have already started making some parts including hammer, probe, cocking linkage and trigger parts. Havent decided on the barrel yet, for testing purposes anything I can find will do, preferably at least 420 mm. Not sure if I want to make the absorber, is it useful beyond 16 j power? If you can help me with dimensions, please do, I am a long time Walther fan and even thou this will not be a real Walther it could be nice to have a knockoff.