Mystery engine, No engine number, sold to me as a 1976 2.0 Options

[fiacra]

I bought this engine from another member a few years ago and had it shipped to me. The back story was that he removed it from a 1976 2.0 that he bought for a -6 conversion. Running when removed, but no other information. I had a project in mind for it, but it has sat in the crate it was shipped in for several years now and now somebody else is interested in buying it from me. The problem is it does not have an engine number where I would expect to find it near the oil tower. That area is completely blank. There's nothing where you would find a 1.7/1.8 engine number. I thought it probably was a factory replacement case, but today I opened up the crate and I've checked all over it and I can't find any clearly identifying marks on the visible areas of the case, such as the mark I've seen pictures of that VW used on a replacement/refurbished case. The oil dipstick is in the right place, the spark plug orientation is correct, it has green fuel injectors, a 2.0 air box for a 75/76, three bolt intake manifolds, and to the best of my ability to tell it is a Porsche 2.0 engine and not a modified 1.7/1.8, a 912 engine, or a bus engine. The only marks I could find were next to the plenum (see pictures), but I have no idea what these mean. No engine number on it anywhere, unless it is under the tin. If I made a mistake, didn't do my due diligence, and ended up with something that is not a 2.0, then I'll take the hit. What I really don't want to do is sell it to a fellow teener and board member, or really anyone at all, if I can't stand behind what I'm selling. I should say the member I bought it from did not seem at all as though they were trying to mislead me. I'm sure he'll be reading this and I'll let him weigh in if he has any more information. So, does anyone have any thoughts on how to figure out what this engine is? Is there somewhere on the case I should be looking? Any other clues? I think it's a 2.0 with a replacement case, but I'd like to be sure if I can before I sell it as such.