HD hasn't ...but another company has .I haven't tried them yet ..but I will next time ....can't remember name ..you might do a search here ..if not try Google
Both current part numbers have a suffix 'A', so they have been changed in some way from the original parts. Read this thread, which has some interesting stuff in it. I suspect the latest parts are better than early ones.
Do they have a distributor like J&P or do you have to buy from them? I don't see an online store for cyco where I can just click away and hit buy now.
You will have to call them to place an order. They are not really a retailer but they will sell retail, just tell them you do all your own work and for your local club members and they will set up an account. I order all my gaskets and seals from CYCO; about half the price as Cometic and very good quality.