As promised some more info
The trigger came from Numrich and is listed as 745. The hammer is from ebay and was listed as 52. But I doubt if both listings were correct, the hammer was DA/SA and the 745 triggers are much different.But it works. I took the half notch hooks of the hammer, that did not work. By blocking the forward motion of the trigger the DA function is gone. But I had to take the lower part of the firing pin safety lever otherwise the slide could not be mounted.
The firing pin safety lever is now just a shim.Blocking the trigger is done by a small plate screwed behind the trigger. Later I saw in my just bought 845 it's done there with just a screw so it is adjustable.
With the shortening of the grip insert the mounting for the mainspring was lost. I made an alu insert where in the mainspring is seated. Depth and diameter based on the mailspring plunger. It's hold in place with the original pin.
Luckily I have a small Chinese mill good enough for these work.
The frame needed a bit longer ears to nicely fit the grip insert. I welded a two pieces to it and milled back.
The grip insert is hold in place with a separate small pin. Both pins are hold in place by the grips.
The lower screw holes of the grips I filled with a piece of wood taken of a matching K-frame grip. Turned on my (again Chinese) lathe and glued with strong wood glue.Next positioned the grips and drilled the upper holes in the frame and tapped M4 into it. The correct UNC tap and die and screws are a problem in Europe so I went for M4.M4 countersunk torx fit's real well.
After that the lower holes could be drilled and then the grips were cut to length.
The checkering I repaired with a square needle file.On the inside of the grip panels I glued a piece of wood to take the force of recoil of the screws. Again k-frame grip wood.
That's it.