I've got an old saddle that came with my Fuji Touring bike (2005) that I would like to get reupholstered with same or similar material as came on it originally. The seat is still in good condition, but the covering is cracked and broken. I just want to put it on an old Diamondback that I use to knock around town with, as I have a Brooks B-17 on the touring bike. Anyone ever have that done? If so. any suggestions for an online business to contact? Thanks very much.

I would check with someone who does auto upholstery. Also motorcycle seats are often done so might check there also. This must be a really comfortable saddle

You might be better off with just a cover over it. I have bought several of these, I never trust water proof seat covers to be water proof so instead when it rains I put plastic bags over the saddle and put a lycra cover over that plastic bag to hold it in place.

Sunlite Lycra Bicycle Seat Cover, Racing/Mountain, Black

Since my usage is short term, I have no clue how long these would last.

silly rabbit! ebay!

Fuji Viscount Seat Saddle 1980s Off A Fuji Flair Seat Road MTB Touring
buy it now: $3.99

Fuji Viscount Seat Saddle 1980s Off A Fuji Flair Seat Road MTB Touring | eBay

Different saddle OP's saddle would be a Fuji Road Sport Saddle since the bike is from 2005 but aside from that you made a useful comment. the Electronic Bay would be a good place to check. I would also get in touch with Fuji and see if they know who might have made the saddle (sometimes they use a different brand but put their name on it).

Though if it is just a random saddle for a knock around bike you could find a cheaper Fuji/Oval saddle or really something from anyone (WTB is a good one price wise and comfort wise)

You can try a motorcycle upholsterer but it's likely to cost more than a new mass produced saddle or a NOS original.

I used Leather ,, sheepskin chamois treated , is in the Auto care department of your big box Store.

then I used a Shoe Dye to change the color.

Check Your LBS, 'take offs' are under $20 .. they're new But removed and resold when a Bike Buyer wanted something else.

Broken in well, and has sentimental value as it has over 50,000 miles on it I hate to throw away an old friend that has been good to me.

You might find this thread interesting, Great restorations with pics.

This link will explain exactly what you need to do.

Recovering Bike Saddle

How is a leather covering treated. I think a lot of commercial ones have a plastic coating. Will wax work OK?

You also need a foam of the right consistency, which is quite hard, not spongey.
A local shoe mender or saddle-maker will probably have the heavy duty tools needed, but I might try this with my old Specialized saddle.