Ok so not staying in the truly retro theme, but I've got a couple of old steel bikes and I'm thinking possibly of putting disc brakes on at least one of them. The front shouldn't be too much of a hassle as the forks will take a disc brake or V's. I've seen adapter kits that use the old brake bosses and some jiggery pokery to put one on the rear, but they are expensive and look a bit crap. I'm wondering if it is possible just to get something welded on to take the brake or if the adapter kits are the way forward. Anyone got any experience or advice?