My calipers are rebuilt original Delco Moraine calipers. The common fix for these calipers is to have the bores sleeved with stainless steel. My Vette calipers are sleeved, but the ones I bought for the Camaro aren't. The only problem with sleeving the calipers, is the rebuilders don't want to touch them. I have a set of rear calipers that were sleeved and then left outside for six years. They still work fine and don't leak a bit. You are right though, these calipers are known for leaking after the bores rust.
69 RS, 427, 4-spd<br />69 Corvette Coupe, 427, 4-spd