I don't think that there is any simple way to get all of the FX into one channel, unless you run the two channels in parallel. Of course this means that you will hear all of the FX, but probably not the way you want them.
It would probably be easier to add the vibrato and reverb to the right channel signal than the other way around. To do this, you would need to re-route the output from the right channel into the FX sections of the left channel, and then into the power amp.
You could add a switch that would disable the front section of the left channel and route the signal from the right channel over to the vibrato and the reverb sections.
Thanks for the technical info. I was just wondering if that could be done. I don't have a A4 or B4 and they seem to be getting hard to find and expensive. I have a Black K100-2 and a Black K200B-2. If one could obtain a PC407A effects board I think it could be done with the B-2 but there would be a little more work involved. Black Kustoms rule!