To make a long story short...we moved just recently and the movers lost the front wheel to my '86 Bridgestone MB-2 (along with my wife's Linus Dutchi 3). The rims are/were RM20 by Araya. Any idea if these would be an appropriate replacement? Are the rims / hubs decent?

Vtg Araya RM20 Super HRD 26 inch Mountain Bike Wheelset w Deore Hubs Bont Tires | eBay

Those wheels look like they are in good condition, the hubs are Deore which at that time was 2nd to top of the line (Pre 1990) for Shimano. Looks like its a Freehub Wheel with a 7 Speed Cassette. are you running SIS on the MB-2? is it 6 speed ? or is it Friction. 1986 was a time just before SIS hit it big.

I'll digress briefly and share your pain. I once moved using "professional" packers and movers and they lost an entire tandem bicycle. Always figured someone on the crew didn't think they were getting paid enough for the job. Moving company eventually stroked a check for a replacement price I was okay with.

I'm sorry, but what is SIS? I'm a little new to this stuff.

Here's a scan of the original catalog

Based on the catalog, it has Sansin AX-20 hubs with a Suntour PT-55 5 speed freewheel. Would the Deore hubs be an upgrade?

Shifters are friction, I think. Would they be good to go with the Deore 7 speed?

I'll try to post pics of the bike when I get a chance.