On my 91 H28
I was able to buy that piece over at west marine, they had it in stock, I don't think it was a harken piece, but it fit perfectly.
I took the one good one I had over there to match up with what they had.
As I recall I didn't spend too much for it, seems like it was less than 20 bucks and I bought two.
Regards
Bruce
Neon Moon