Blimey! No more buggering around with abrasives, dust, frustration....and not quite getting the results I want either! I just talked to the guy at P&P Services and they will blast each wheel for £10 and prime for £5....total for 5 wheels = £75. And they will turn them round in about three days. I'll take them up on Monday.
Then I need to decide whether to get Brian to two-pack them for £150-200 or spray them myself, a la Practical Classics. There's a lot to be said for the professional job, but right now I need to slow down on the money-spending, especially as I now need to get a new sender unit; and tank repair kit, which will set me back £45 plus postage.