The Sanli base I found appears in very good nick. Two problems. It is a very small 16" wide cut and the rear axle has detached from the part where the wheel stub is attached.
It's actually a shame I have to transfer the plastic Victa bearings as the original bearings are full metal casings and the wheels are retained on the Sanli stubs with nylock nuts and washers!!
The fittings for the Sanli base seem well designed and of good materials. I was impressed to be quite frank, and would love to use any other bits I can.
You are right about the wheels. Very good solid construction. They feel more substantial than Victa's. Years will tell but the tread is in near pristine condition and I presume this mower went through a bit of use before being discarded.
Maybe their axle joints are an Achilles heel?

Ahh, if only victa had kept producing the thumblatch catcher series, they would be in better shape today!