Hi Dave,
Yes I have put the 2132's in both positions but may experiment a bit with one 2132 and one 4562. I dont possess a pair of headphones so havent tried the headphone output (maybe on my xmas list though....)
The MCL 5/6 mod is not difficult but you need sharp nosed wire cutters to get to the right capacitors nestled amongst other gubbins (thats a technical term). You only need to cut the wire so the bits stay in place and could be soldered back if need be I think. I used toe nail clippers but dont tell Leo or Stan.