You're right, Terry, five guitars would be posy, but two or three is acceptable, particularly if you're doing a two to three hour set.As of now I usually use (solo accoustic gigs):
Martin D18 EADGBE/Dropped D Mugen '78 Open C Washburn D34 Open G / Open D
This keeps the retuning to a minimum.
Who Knows where the Time Goes fits open D - I nicked the arrangement from Dave Cousins of the Strawbs years ago. The folk process has done a little work, but audiences seem to like it, which is the main thing.
Glad I started this! :-)