Welcome to the Forum!
I can't help you much with the model, but sometimes there's a VIN stamped on a plate on the tunnel... or on the bulkhead in the engine compartment.
For generic parts, I like using Dennis Kirk. (
DennisKirk.com - Motorcycle, Harley-Davidson, ATV, Dirt Bike, Snowmobile, PWC / Watercraft Parts, Apparel, and Accessories ) They have a good assortment of all sorts of parts and accessories for all sleds. For specific AC parts, finding a good dealer is key. A helpful dealer will save you money over time.
Any TC3W rated oil will work in that sled, some smells better, but all will protect the engine.
I would change the chaincase oil, grease all the grease fittings in the suspension, oil the tie-rod ends, check all the suspension wheel bearings, make sure the clutches are clean.. I would probably replace both the primary and secondary springs and get a new belt... If it's a liquid cooled engine, drain the antifreeze and refill with fresh. Check the brake pads for excessive wear and adjust the brake cable.
Other things to look at...
Pull and clean the carb, replace all the external fuel lines, replace the fuel line and weighted filter inside the fuel tank, maybe replace or rebuild the fuel pump.. any rubber products have probably deteriorated to the point they are not usable over the 10 years...
Check the shocks on the front and in the rear suspension. They may not work at all after such a long time of non-use. Check the skis for usable runners, too. Sometimes the seals in the shock will dry out, but may come back some if the shock is worked back and forth a bit... Check the track really well, if it was sitting on the ground that long, it may be rotted to the point it will need to be replaced. The springs on the rear may also be sagged, if the weight of the sled was sitting on 'em for that long.
Lots to do to make it perfect, but it could be a really fun summer project!
Here's a company you can get AC parts from online if you don't have a dealer near you. You can also get the part number from the online microfiche so you can be better informed if you do visit the dealer...
Alpha Sports - Arctic Cat Snowmobile Catalog
There are a TON of threads on how to work on sleds in the Engine/drivetrain section of the forum. Check the "stickies" at the top of the thread and you will have enough reading to keep you occupied for a few evenings!
Good luck in getting your sled back on the snow! Consider posting some pics as you go.
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2007 RMK 700 155", 2008 RMK 600 155", 2006 RMK 600 144", 95 Prowler 550 2-up, 1990 Indy 650
RIP, destroyed by fire 1-22-2008

04 RMK 800, 05 RMK 600, 02 RMK 800, 97 RMK 700
http://www.avalanche.org/accidents.php