Of course, I promptly ran into one of those freakish hail storms. So, rather than trundling off ever eastward in the morning, I ran a few errands and stopped by a tire shop. I'm sure we've got the tires. Just call back with the tire sizes. Well, it wasn't quite that easy.
Nothing ever is with travelling, it seems.
Apparently, the tires on the trailer are older than the trailer. They're probably a 220 or a 225. Just bring the trailer 'round. So I did. A few hours later, Rolling Thunder sported 4 new 8-ply steel belted radials, a thumbs up on the brakes and freshly greased and packed bearings.