Cat / Euro Trax Wheel hub internal dia and width?

Hi Gang,
I have picked up a large wheel dolly that employs Cat / Euro Trax Wheels (The Large Knobbly Type).
The axle seems to be of the homemade variety and is bent beyond repair, it is only around 30mm dia and made of Stainless Steel so not the standard Trax type (50mm dia Aluminium).
From my understanding they employ either a fast type bearing (ball bearing) or Roller type bearing that has a roller washer either side that the roller click into.

I am looking at fixing it up and was wondering if someone could provide me with the internal diameter and width of the trax wheel hub? Sadly I am nowhere near my sailing club to check for myself.

Thanks

_________________
Hobie 14 Turbo (~1979)
Hobie 16 Carumba (1983)
Hobie 16 1990 (storm damaged)
Hobie 16 1996 (my latest)