Amtron - Amtroncraft - High Kit
Besides the Coax-Wax, don't forget dB Grease. Einneuesleben89 used to sell it by the jar. Makes the electrons slip through faster, and if you use enough of it, your coax will actually have gain instead of loss.
The Heathkit HL is one of Heathkits last made amps. It probably dates from the mid to late 's. It is similar to the Heathkit SB, Family Constellation ads a newer case capwap.org amp uses Eimac Z tubes. A max of W input drive power is required.
I purchased the SB & SB manuals so I would have a reference for the parts needed to convert the HL to 10 meters. I saw an SB conversion kit from Heathkit on eBay once 2200 was outbid on it. That kit would probably contain all the parts necessary for the 10 meter conversion of the HL.