I do like the look of that, very nice... definitely a worthwhile upgrade.
Slaters (very much “the Old Firm” for this sort of thing in the U.K.) do a 19mm Steel disc wheel in O Gauge, that looks like the first thing to try.
I’ve now sourced a spare pilot so I’ll pay a quick visit to Slaters website and convert the spare pilot when it appears, and see how it develops.