New ride is festering a lot of new questions

[va72longhorn]

Got the Longhorn replacement home Sunday, finally. Nice, unmolested ‘72 C30 with a 12’ dump. Well documented history as I’m the third owner. Original farmer had it from 72 until he passed in 2013. Family sold it in 2016. Every yearly inspection sheet was in the glove box. Dump cylinder added in 1983, Original 350ci was overhauled by the selling dealership in 1993 at 78k. Rear replaced at 2006 at 124k. 130k on it now. Repainted once back when it changed hands the first time.

SPID and build sheet reflect;
Custom Deluxe Trim
Cloth bench trim ( seat cover’s been replaced with an aftermarket vinyl)
Dual wheel conversion
AM radio ( currently not working)
WC door mirrors ( painted)

Not on the documentation but original GM accessories on the truck ;
Extreme tow hooks ( I verified casting numbers)
Bumper guards
Lower wood grain trim
Spotlight ( I think it’s GM, but not 100% sure)

Now, maybe someone can help, but a few things have me baffled;
1) the wood grain trim. I thought that was Cheyenne specific?
2) it has the medium duty style steering wheel with the large round billet horn button. Was that an option? Standard with the dual wheel conversion maybe? I’d rather have the c10-c20 style.
3) I think the Custom Deluxe trim included the cloth seat with color keyed mat, although not houndstooth. If that’s the case, is the separate option of “ cloth seat trim” changing it to the Houndstooth? I prefer the houndstooth, plus I know the original non-houndstooth covers are hard to come by. It does have the interior door light switch and the rear window chrome trim that comes with the deluxe package.
4) the chrome grill and bumper. Custom Deluxe package?
5) lastly, this dreaded 4:57 rear. Drove it about 120 miles coming home, taching 3k at 60mph. No wonder the SB 350 needed overhauling in 79k miles. I think it’ll pull a house down ( found haul tickets in the glove box for 6-7k pounds of stone and stumps) , but what’s the easiest way to add an overdrive without a lot of work and without losing the originality of what the truck was built for?