My vintage caravan tyre size is 575 x 6.00 x 16. At some point I would like to replace these but can only find 550 x 16 and 600 x 16, would either of these be OK to fit and if so which to plump for? Thanks.
6.00 x 16 will be fine. Years a ago some tyres were marked with two sizes ie 5.75/6.00 x 16 which means that they can be used as either 5.75 or 6.00 width tyre.