We replaced ours 2 years ago. Do all Bomfords with tank idlers have ones the same as ours?

Yes, they were the army surplus of the time, I guess 1950's?

Some of the Bomford vans have not got the tank hubs like yours, but have a single idler each corner welded to the lopped off spoke centres, some had the 8 spoke wheels, some the back to backs.

Some Jackson vans also have got them fitted the same way.

I was going to do this with my Bomford wheels, but have now decided on ball bearing hubs given the speed It'll be doing behind the Marshall.