I don't think that the Mossberg 800 or 810 series of CF rifles were very good. Some of the 800s had a plastic trigger housing that could become soft and distorted if left in a hot place, like a pickup rear window rack, and not work properly when they cooled. The Revelations were house-brand guns made to sell at an even lower price than the Mossberg branded guns, so they generally had lower grade wood and finish, anything to get the price down.
I think that it is hard to justify buying in an older entry level CF rifle, and almost any house-brand CF rifle, when the excellent Marlin X guns are so inexpensive and so accurate.
Since the Mossberg 800/810 rifles have long been out of production, parts are going to be a problem that won't get better and since is such a basic bare-bones rifle, it wouldn't seem cost effective to rebarrel it, given the short cuts made in the donor. The best way to gage the availability of parts is to see what GPC has, 'cause they likely have the last stock of available parts. www.gunpartscorp.com.
You might also inquire at the Mossberg Collectors' site, www.mossbergowners.com
, or with the Mossberg Collectors group's honcho, Vic Havlin, at his site, www.havlinsales.com.
Bottom line, I wouldn't buy it unless I could get it for under $100 and was prepared to sell it as parts if it becomes non-functional. For around $300, the Marlin X guns are, IMO, a much better package that is a lot less expensive to rebarrel via Savage 110 series specs barrels if you want to go in that direction somewhere down the road.
PS - I have a Mossberg CF house-brand rifle, an old lever action Mossberg 472/479 in 30-30 that is a Coast-To-Coast Hardward house branded "Master Mag CC779. Stained birch wood and dull, low/no polished, steel, but a functional, no maintenance, knock-about truck gun.