Your Handitwin is an Elto – the lower priced line built by Evinrude at the time. Many parts are interchangible with Evinrude’s Sportwin. Peter Hunn’s "The Old Outboard Book" lists the price at from $20. to $125, Depending on condition. I always liked the antique Eltos. Everything was out in the open. You didn’t have to take a cover off to see if he float pin had poped up, indicating fuel was in the float bowl. The one I had was bought by a fellow AOMCI member for $50 and he couldn’t get it started. I cleaned the fuel filter & carburetor passages, sealed the float, installed new check valve bumper, new spark plug wires, cleaned & adjusted the breaker points, and built up a bad bushing in the gearcase. It ran like a top. He said he learned a lot watching me and decided to stick to newer outboards. Then he gave it the me. I ran it twice in 10 years and sold it this spring for $40. to make more room in the garage. Some highly polished Handitwins have gone on Ebay for $300 – but those are museum pieces and it would be criminal to get them wet. . . 🙂