If you're navigated to this page, you're looking for either Heathkit parts or manuals.
Now, sorry to say, I have neither.
When the Heathkit company was in Benton Harbor MI, and went bankrupt, all parts were either sold off or scrapped. There are none. Zero, zip, nada.
I sure wish I had some, but alas, none to sell.
Common parts like resistors, capacitors, things like that can be obtained from Mouser Electronics or Digikey.
When the new owners of Heathkit came back, they wanted all copies of their manuals removed from the 'net. If you look, sometimes you can find them on overseas websites out of the reach of the company.