part does not match 39-221, please advise

Thanks for writing in. While your operator has a different base, I think there's a good chance one of our replacements should still work for you. Do the dimensions of the 39-221 match? If so, it could still work for you. The biggest difference is the offset in the link arm; if needed, you could always swap the arms by drilling them out and using a rivet like our 62-014. You also might want to look at the 39-315, though I fear the base is less wide, so it may leave a gap. See what you think.