TQA, Thanks for taking those photos of your winch bases. If they are that badly corroded, they must be made of cast aluminum, which in a salt-water environment, has eroded over time.
No bases at all came with my recent purchase of the Barient 28 flat tops, so I am looking around for a pair of them. But, I take pause, now that I see that the original bases were made of aluminum and have a bad reputation.
The primaries that I already have on the boat are self-tailing Barient 28s. I have not taken them apart, but they appear to have stainless steel bases. I wonder if those are after-market.