[Boatanchors] Converter info

[RAY FRIESS]

I'm hoping someone can help me.  I have an old old homebrew rig which is labeled as being a 6 meter transverter.  On the chassis is a PC board that says International FCV-2.  It is missing one tube, but has a 43 mhz crystal in it, so if it is in fact six meters, I suspect a 40 meter IF output.
I've searched online, and while I found an old International Crystal catalog, there is nothing in it about converters.
Any comments, help, or thoughts would be appreciated.  I did find one reference online in an email from a ham who had one and he indicated in the post that his had a 6BQ7A as an RF amp, and a 6U8 as an oscillator, but that was the extent of it.  He was also looking for a manual years ago...