That is the mount for Columbia's integral kick stand. You may be able to find the parts you need if you look on eBay, call Memory Lane Classics or check out a swap meet like the one in Trexlertown, PA this coming Sunday. I see a hole drilled through the frame behind the original mount. Keep an eye on this, as there is the possibility this hole could weaken the frame. It looks like someone mounted an aftermarket kick stand there.
