It may be time to bite the bullet and buy a learning Cinema.
You know that code 043 works your mitsubishi "A" mode VCR. I'd suggest that you make sure your second VCR is in "B" mode and try the code search method as described in your cinema manual. If there's a device code in there to work a Mitsubishi in "B" mode then that should find it.
Another strategy for finding device codes is to try codes listed in the manual but for other manufacturer's VCRs. Again, make sure your second VCR is in "B" mode. My Cinema7 manual lists codes 0043, 0048, and 0067 for Mitsubishi VCRs. Look at any other maker's list that includes 043 OR 048 OR 067 and try all the other codes listed with those maker's VCRs. I have a Go video VCR that didn't work with any codes listed for Go Video VCRs. I found a Samsung code that worked using this method. As it turns out, early Go-Video VCRs were made by samsung.
If all this fails, then get a Cinema7 learning (7800) model. I've seen them as low as $16.50 at Best Buy, and with the learning feature you can teach a second device all the basic codes to run your "B" mode VCR using the original remote.
