Victa wheels are 150mm or 200mm diameter; 9/16" axle size. For axles on that unit, I'd just use 9/16" Grade 8 high tensile bolts [which aren't fully threaded], with a nut on either side of the bracket. That's the basic setup I used, to put Victa wheels on my home built oxy bottle trolley.
Ball bearing wheels for 1/2" axles are cheap enough too; repro Honda wheels are a type that I've used.
Cheers,
Gadge
"ODK Mods can explain it to you, but they can't understand it for you..."
"Crazy can be medicated, ignorance can be educated - but there is no cure for stupid..."
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