I changed one of my cabin top winches on my superseal last winter, for an Antal XT16 self tailing, purchased from TCS Chandlery in Poole, cost March '24 was £389.00.

Not sure about the holes but fitting on the 26 is easy with good access both sides.

This was the cheapest ST winch I could find and works fine.

Philip

If alignment of fixings in the new winches remained the problem you could use an intermediate plate e.g. 9.5 mm aluminium ,that is thick enough to countersink and tap for machine screws.That is what I did to fit a new keel hoist winch ( also an Antal) on a Seal 27,allowing the new bolt pattern and with the very great benefit of shifting the winch back clear of the sprayhood and into good alignment.

If slippage of thin lines in the jammers is the basic issue you can use a thin piece of anodised aluminium flat laid in the base to reduce the jaw.Lines slide on this and with the ends turned slightly down the flat is trapped making the workaround convenient and durable.

Appreciate that your 275 differs from the 27 but there appear to be similarities for line handling here.

Peter