I've just taken the AE tires off the wheels (thankfully, they weren't glued) and they don't have inserts either. Without a hobby shop close by nor any desire spend more money on this project, I'm just going to rummage through the garage and see if I have some packing material or foam padding from which to make some inserts. Anyway, no worries. I'm sure the tires are going to work great.
While I have the tires off, I couldn't resist going after those wheels with some hot soapy water and a tooth brush. Overall, I think they're gonna clean up great. There are some rough edges to remove on a couple of them (should be quick work at the lathe or drill press) - nothing too extreme that can't be cleaned up.
I'm relieved that the wheels are in such good shape and aren't broken. I reckon that nearly every other part for this truck is readily available either as original, re-re or aftermarket. I could be wrong but I believe these wheels are exclusive to the Outlaw and as such, would be rather hard to replace.
Anyway, I'll post more pics when I have something to show.
