[WarBaby]

Yes a Model 7, they look very similar however the ejection port on the model 4 is on the left side of the action. Strange to get used to!

 

[WarBaby]

Yes, natural horn is subject to worm holes, I thought it looked like horn, but was not sure Walther used horn.

They did indeed use horn, especially on the earlier models.

 

[WarBaby]

As the Mod 5 is essentially a Mod 2 then this may widen your part / bushing search? Best to try before you buy - though I guess such parts would also be as rare as rocking horse shite!

Earl probably has it, but you're gonna pay. Even the somewhat common Model 4 parts are, well, expensive for just a 'cheap' pistol.