I have a secondhand Henry 3KD premier on hand that I consider acquiring. The amp is the version with the Eimac 3CX1200D7 tube. Questions: what is the availability of the Eimac 3CX1200D7 tube and what would a typical price be for a replacement tube? What are your impressions around this Henry amp? Any known problems, issues or hard to source parts? LB3HC