Well....ooops is all I can say, oh and this.
Siegried (Saffy) is an excellent and fair dealer, I certainly didn't intent pointing a finger, as I've bought alot of items from him, all excellent. Im certain this is a genuine mistake. Thats assuming im right in my identification, of course. ....I do know that Zunder and Pzgr40, would know instantly. I bow to their knowledge.
Eitherway, both the case and proj are in excellent condition, so I think you're still quids in.
So if I waffle a little more, I think the correct HE projectile for the case has a hemi-spherical end to it, and small "nipple" of a fuze....sorry, don't have pic. (7,5cm SprGr 38 HL)
As for the projectile, I'd go find a nice Kwk40 or Pak40 Case and wop it in the end.
(Kwk - being TANK gun, Pak - being Anti-Tank gun....if anyone didn't know)
Rich