I don't think there's a riveted box that held me back before!
It's not like we're afraid to void the warranty by now
Just drill the suckers out. You need a drill just slightly larger than the rivet's post. If the drill won't fit in the rivet hole by a fraction, it's usually big enough.
When inside, look for smells, mystery blue smoke residue, arcing and all the usual.
Does the timer output 240vac to the tranny?