Not sure if my dog is a GSD like I was told - Page 2

nope she didn't,  And to me he looks crossbred.  Can argue that all you want. He doesn't look pure to me and the OP doesn't think so either or they wouldn't be asking.

Trust your gut, it's normally right.

Personally i see a lot of visual similarities between the GSD and Malinois i would not at all be surprised the breeds are related. Take a look at my wife's dog when he was a pup, it looks very Mali to me but his pedigree is all GSD. Like others though, i am suspect of calling your dogs recent lineage German import just based on the size. There are a lot of GSD breeders who love to throw around 'German Import', "...from champion lines...', '...schutzhund xxx in the pedigree....' The reality of the breed is that if you go back far enough in ANY pedigree there has to be SchH titles and of course there are going to be dogs that earned high show ratings and guess what, all GSDs heritage is from a dog in Germany 
But who cares, if you are not trying to breed and show him, just work with him, give him some type of job and enjoy the relationship

ThE dog I met at the vet's was not overweight, either.

Your gut is only usually right if you have some idea what the heck you're looking at. ;)

Not to brag, but I'm fairly well-versed in GSD, and I'm sticking to my story that the dog is not a dog I would personally be interested in, as my goals are far different, but he's a pure bred (note: pure bred doesn't mean WELL BRED) German Shepherd, nonetheless. I am not going to argue with you, bzcz. I don't even see why there's a question, except the OP is inexperienced, as you also seem to be, and asking those who are more experienced. Malinois, he certainly is not, LOL. BYB American lines, all the way. GSD all the way. 

Your dog clearly looks purebred and most likely american lines. He appears significantly overweight in the pic. He is a very tall, washed out dog, but so long as you think he's wonderful, that's all that matters.

It's not only American lines that get big. My 2nd GSD was 100% GSL and he was a very big dog too and, again, NOT over weight. Size is very hard to control or predict; it's not unusual to get very large individuals in all breeds. That's why there are size DQ's and wickets. I was often asked asked if my 126 lb male was a King Shepherd ror a Shiloh. I never heard of either when I got him in 94.

All lines have large individuals. Going off photos, however, that dog is American, primarily, if not exclusively (for the last several generations at least...of course we know where the pedigree leads to way back...) which is why I said that. I did not mean to imply that only American lines get big. 

The dog is fat, too. He could stand to lose at least 10lbs. 

Lol size it's hard to control.  This is funny. The bull studs breed and predict size every day.  Yep I'm inexperienced, keep telling yourself whatever makes you feel better. 

We probably shouldn't even get into progeny or kennel group classes where they are all #gasp# uniform. Cuz size is so hard to control

For all purpose you got a rescue. What difference does it make if he has a splash of Chihuahua.. If you where interested in quality you should have gone for purpose breeding. That said, big ole american GSD! agree with Jenni. Now hug him and pet him and squeeze him but dont call him george. Get help with that aggression if you need it, better to cut that out before its too ingrained, if its possible.

Good luck to you!!

BTW all you "experienced" Einstein's.the OPs dog is the first one laying down. Not in the second or third pic. We inexperienced folk can tell that those are different dogs. the OPs dog laying down its hard to call overweight