Note that type 1 swing axles (and their matching tubes) come in 3 different lengths-
1961-'66 are short axle/short spline (26 11/16")- gives room for the extra offset of disc or type 3 brakes and some leeway for different wheel/tire combinations
1967 only long axle/short spline (27 13/16")
'68 and newer (and I believe all type 3) long axle long spline (28 7/16")- the same track (or very close) as type 1 irs.
I don't know what the 1960 and older split case trans beetles use for axles and tubes; I do know that they are shorter (exactly how short I don't know), the axles themselves are thinner, and that they can be bolted to a later swingaxle tunnel case. Al