G'day wce, Max and MF,
I guess Model 528 is a fair call.
Max will be a better judge of that than I.

Victa never used Briggs in this decade.
It presents as a a mid-1960s chassis with a 1970s Briggs 10 Series.

Yes, the motor does not look right at all - way too front heavy,
it must have put a bit of strain on the rear axle when turning!

Cheers
-------------------------
Jack