Anyone heard of Tech Instruments Corporation?

Yes

Tech Instruments and Harvard Electronics produced Futterman designs under contract or licence

I have a Harvard Electronics H3 with 6FW5 outputs

Which output tube is in your H3?

Mine has 6HJ5. I just found the history. You are correct. So it appears Julius himself worked on this amp. What makes it likely those are his initials is that any amps needing service back then were sent to him personally.
Cool.

I'm not clear on power rating though. The article I found states it's a 40 watt amp but doesn't say whether total or per ch.. The amp has 4 6HJ5 per side.

I have great working H3 I've had it since 1979 so it is older than that, any idea on its' value>