I have a 1993 Bridgestone XO-2 53cm 26" wheeled road bike. Fell from the sky into my lap. All original with seat, tires, chain, bar wrap, cables and housing all shot. Looks like it was ridden very little and time alone has deteriorated these components. Not my size bought to resell so should I replace with high end parts (that the bike deserves), cheap parts, or do nothing and let the new owner set it up as they wish. What would you do?

Don't touch it. You won't add much value to it but you may make it harder to sell especially if you throw a lot of expensive parts on it. The B will decide whether to ride it according to spec or to upgrade it. The '93 is a fantastic bike. This is mine:

No pics?

What's wrong with the chain and saddle? Does it have to have high end parts? "Fell into your lap" makes me think you got it cheap. Would a set of Jagwire cables, Pasela tires and some tape really make you upside down on it? A bulky chain could possibly be cured by soaking it in something, maybe ATF? As decent take off saddle from the LBS will fix that issue.

Don't these have a huge following? Or just the XO-1?

Agreed that replacing consumables might make sense and that a post without pics is no fun. The OP is talking about putting on high end parts and I don't think that is cost effective.

Yeah it's a great bike. Same geometry as the XO 1 but a tad heavier because of the tubing set.

Apologies for no picture hadn't downloaded at time of posting. Seat is a goner Lycra fabric torn. Tires have split sidewalls. Bar wrap torn. Chain is just crusty. Housings split and rusted.

Looks intriguing to me
dogtown, was that not a 70’s nickname for Santa Monica?

Chain may be able to be saved the seat is a Lycra mess. It was born high end $900 MSRP in '93 I'd say that's high end. I did get it cheap that's what I meant to imply. Brooks seat, Schwabe tires, and decent chain, cables and wrap is $250 or so. Don't want to cheap out and a LBS takeoff is out of the question like shopping at Pep Boys for tires for a Ferrari. Should be able to get $1000 to $1500 in Cali marketplace.
More than a huge following according to the Sheldon Brown site "Cult" following and only 1500 made in 1993 also from SB site.

You get the prize

I think your sale value is optimistic, but an interesting bike.

Bridgestone seems to be one of those brands that gets higher prices just for the name. Usually when you get a really good deal on something like that, the best way to maximize profit is to just turn around and sell it as-is. As my realtor friend once told me, "Easy money is the best kind".

I disagree that it must be high end bits. These bikes have a following but I don't know $1000+ is possible especially if you have to ship it. If it was me I'd strip it to frame and clean and wax it and clean all the parts. The cable housings should be lined so, if they clean up nicely, just good quality wires are needed. A good take off seat and some decent skinwall tires and I think your in business with a good looking functional bike that will sell well but it is a still a bit of a blank slate to Bridgestone fan. Did these even come with a Brooks as OEM?

You might think it looks smashing with a honey colored Brooks saddle and bar tape and spendy cotton tires but to a potential buyer the Brooks might mean an uncomfortable ride. If you were a novice that always wanted one of these would you rather pay $500 for a rideable bike that you can fiddle with and change things or a $1000 for one that someone else tricked out and isn't really what you had in mind?

Face it, things could be worse eh?

Pic from the interwebs, not the OP's bike

The stuff you're considering changing out is the stuff that I normally would swap out anyway as a buyer, with the possible exception of the chain. I wouldn't pay a premium on stuff I was going to trashbin, anyway, unless you happen to choose exactly what I was going to do. Pretty unlikely.

I just sold a decently nice '92 XO-1 with mix of high-end and original parts for $850. $1000-$1500 for a thrashed XO-2 seems wildly optimistic.

There was a 58cm XO-1 sitting on CL in the Los Angeles area for months at $1200 earlier in the year. It's not listed any more, don't know if the buyer took it down or it eventually sold.

I'd say your too high on the price. Just service it. It is cool, but not a Ferrari.

I found this one at a garage sale for $80 several years ago. It was while I couldn't ride, so I flipped it out of season on ebay for $255 with the buyer paying ~$100 for shipping.

Clean and wash it and sell it as is. Or part it out and just sell the frame.
Make good pictures and any potential buyer might pick it up as a project. I would only put new parts on if I had them lying around. Anything you have to buy will take from the profit and most buyers who buy it as a project bike will just tear everything off anyway.

So some good advice thanks, coming from someone who owns one your advice carries a little more weight than some of the others. I have to make it ride worthy I think to get the best dollar. To have a buyer pull up to a bike that can't be ridden will insure a low ball offer. This isn't Iowa people here fight over the things they want and as a result pay top dollar over what they would pay in a landlocked state or seasonal riding state. I now see that making choices for the new owner is risky. I have a take off seat and most of the other stuff but what I don't have is 26x1.4 or similar tires laying around. There is no quick fix for that unfortunately.