There are basically 2 seals that need service commonly in Mag series air/oil forks: The air needle valve in the top cap, via which the forks are pressurized, and the main oil seals at the top of the lower legs.
The main oil seals can be bought easily. Enduro Fork Seals sells'em online. Your Mag 10 takes the same seals as the Mag 21. These seals don't fail that often, mine are original after 18 years. I purchased a spare set, nonetheless.
The air needle valve is unobtanium, but you can make your own cheaply and easily. I went down this road this summer: Post here:viewtopic.php?f=1&t=268636&hilit=mag+21
If you wish to service these forks yourself, I and some others (Fluffy, I'd bet) here can walk you thru it... It's not difficult, but it involves alot of disassembly and service proceedures that simipler forks don't.
Getting these serviced by commercial outfits is becomming very difficult these days, making it worth being familiar with their service procedures, if you wanna keep'em going for a couple more decades. Takes nothing more fancy than some snapring pliers, a good pump and normal tools.