Lewmar is a great
winch, but it's very unlikely that the baseplate will fit the same holes as your Barlow.
I just bought a Lewmar 46ST to replace my non-selftailing
Barient 21 main
halyard winch. I wanted a little larger winch, but mainly I wanted selftailing for the main
halyard. But I didn't really want to have to change the wedge on the
mast. So the
rigging shop fabricated a 5/8"
aluminum plate to act as an adapter between the winch and the wedge. They drilled and tapped the holes for the Lewmar and then I had a nearby machinist drill the holes in the adapter plate to match the old Barient baseplate. Then I attached the adapter plate to the wedge and then the Lewmar to the adapter plate.
The
rigging shop was Port Townsend Rigging and I highly recommend them. VERY accommodating!