The starter area is also full of crud confirming my suspicions that the engine and trans needs to come out and be checked.
Now, is this the first forklift you've acquired?
And/ or are you under 30 years old?
You're really tearin into that unit!
Was there specific reasons to take off the head??
Did you run it before you took it apart?
Reason I ask, and I can't remember personally what I would have done in my younger years, but I suspect you are
looking for an excuse to -pull the engine-
I think at my age now (52) I would be looking for lots of reasons to NOT pull the engine OR split the trans off it unless it was a dire necessity.
When I was younger....perhaps, just to satisfy my curiosity and ensure a superior job. Now-a-days, I'd be pressure washin the starter area reeeal good, and call it OK. But you did find missing bolts.....
I now being a bit older and less enthusiastic, tend to address the essentials and let things unbroken remain so until if and when they change states on their own. Hours can wrack up just the same. I think back at the many hours I have spent doing non-essential 'behind-the scenes' stuff that will never matter, and sometimes I cringe.
NOT TO DETER YOU!
Keep up the good work, I'm sure you'll end up a pristine classic given your approach to details!
EDIT:
Wait, wait.....I checked your profile.
Retired.
That explains it, hobby project.
You will have fun and enjoyment with this!