I've got some bubbling rust on wings are rear tub corners which I'm going to tackle when the weather gets warmer (was trying to fit a new year bumper yesterday and get no pleasure lying in the snow).

Have you tried one of those 'Chips away' companies? There may also be someone local. I find some of the facebook classic car groups are a good source of contacts. When I wanting my rear core plug replacing (complete engine out) I was quoted some fairly wild prices, but a local bloke (recommended on FB) did it for £150.

"Y mae dafad ddu ym mhob praidd"
1972 4/4, 1981 MGBGT, 1984 FLHT1340, 1980 XLH1000, 1990 ZX10