Lyman Great Plains Pistol Screw

[Ranger 1755]

Hello all,
I have an older Great Plains pistol I built from a kit around 35 / 40 years ago. The head of the lock bolt / screw broke off. Trying to find a replacement. The shank measures around .154 but does not match up with any of my inch or metric dies. Does anyone know what size it is, have one for sale or know where I can get one? Can't seem to find it on any of the regular supplier websites so getting frustrated. Thanks

 

[Jim in Wisconsin]

sounds like 4mm - .7 and .5 are the two thread pitches. The common one is .7, the fine pitch is .5

 

[springfield art]

I've seen Lyman pistols that guys have customized to look really "period". I don't think they make them anymore? Maybe I'll grab one up if I see one used.