[mythtv-users] Merging two mythtv installlations into one?

[sp]

I've got two completely separate installations of mythtv 0.22 that I would like to merge into one. 

Setup #1: HDHomeRun ( 2 x ATSC )  = 2 Tuners total
Setup #2: HDPVR + DirecTV  = 1 Tuner total

I don't use any of the various mythtv plugins and use schedulesdirect as a source of programming info under both setups. I would like to merge Setup #2 into Setup #1 and retain my recording history and schedules. I'm not so concerned about moving the recordings from Setup #2 (if I lose them, so be it). However, the most important thing is the recording history that has been built up over probably a year or so ever since I got the HDPVR.  To summarize:

Must haves: Recording history, schedules
Nice to have: Migration of existing recordings
Don't care: Front end configuration data, plugin data (residual) 

Has anyone had any success doing something similar? I don't mind getting my hands dirty but if anyone has any "Don't attempt to do it unless your tolerance for pain is extremely high" sort of experiences, please do share.

-sp