drilling out screws
hi Slimstar
I have had some experience of drilling out screws in conjuction with using a screw extractor, though this was on some much larger screws.
I got the screw extractors from screwfix, they are basically an opposite thread screw, you drill a hole in the centre of the screw to be removed, screw in the extractor which screws in anticlockwise and when its tight you start unscrewing the screw your trying to remove. Sounds simple in theory, this method may be worth trying if you can get a small enough screw extractor, and are confident to drill a very small diameter hole in the screw.
Another suggestion if the above is a bit delicate, would be to carfully drill the heads off the screws, but the risks are the drill slipping off centre and damaging the surrounding casting or leaving you with nothing to grip the screws and being unable to get the remaining screws out of the valve body.
One other thought if you have any screwhead left would be to hold a soldering iron in the screwhead, to warm the screw and surrounding aluminium, you may find the different metal expand at different rate and may help.
Well these are only suggestions and I certainly can't promise them to work, but I hope they do. I don't have any complete ocv valves, but have a few of the internal parts and some of the gaskets that seal the valve body and the chrome top part to the tub. i've also got a few pump components if your stuck there.
By the way Steve, nice spinarinse there, if it's not been said earlier the white top surround to the spin can didn't come in until the later model, the one witht the black plastic lid, the one before Craigs above, prior to that they were the same aluminium as the main part of the spin can.
All the best both with these restorations
Mathew