Turned out that they were 33mm and once replaced with new rubber and new brackets my horrible clunking has also gone.
Had a new main muffler fitted which sounds good and has removed some of the exhaust leak, but suspect I've got one at the header also as it makes the horrible tick at idle when cold (pretty sure its header rather than lifter). Had to do a few random items, transmission pressure sensor along with full flush and filter change.
