I have posted this elsewhere before. The successor to Barlow/Barient is in Australia, and still supports both lines, with parts, diagrams, etc. It's called Hutton Winches, LLC. The phone number is +61 2 9623 2448. You can email a really helpful guy named Alan (sales@huttonwinches.com).
Winches are really easy to work on (as long as you don't drop parts overboard). I doubt you will have to drill any holes to repair the winch, so give it a try. Come back here for more help.