Having no further excuse, I got myself a bucket of hot, soapy water, and scrubbed off the leading couple of feet of the canvas apron (and found another metal rod in the process, which has also been polished.) I'd love to toss the apron in the wash, or replace it, but it's stapled to the cloth beam, and I'm just not sure I'd ever get it back on as nicely. So I scrubbed the yuckiest bit, and it's drying right now.
Once the apron is fully dry, I'll put the rods back, push the loom back into its corner, and ignore it for a while. I have sewing that I need/want to do, and I need the floorspace. But while I'm sewing, I'll start planning out the warp I want to put on it. I have this wonderful towel that is waffle weave with alternating striped bands of tabby weave. I've never used it because it's so nice, and I'd like to make a bunch of them. Everything I read says that waffle weave loses about 30% as soon as you take it off the loom, so the 36" width will help a lot.
And if they come out well, I'll make a few and send them to the lady who gave me the loom. :-)