I was just about to go into war and peace about attempting something quite so daunting on your first go and was smply going to remind you a thing about aftermarket parts
NOTHING EVER FITS.... EVER..
But I see you (or actually and more luckily the garage) has just found that out.
Good luck with getting it finished, just one word of advice, don't get hung up on "it's supposed to be finished today" because that date will never arrive.
Just keep at it, overcome each issue as you find it (there will be more) and eventually, if you have the right people working on your car you will eventually get something back that you can go hoon in.