Note that the "Stephen Reynolds of Oregon" mentioned in Steve Gardham's article at  Mustrad,  which originally appeared in  English Dance and Song,  is the Steve R who started this thread back in 2003.

Interestingly, the beginning of 'Over Hills and High Mountains' is echoed in some examples of the 'Shrowsbury for me' / 'Boys of Kilkenny' song family, which overlaps significantly with the 'Streams' / 'Green Mountain' group. The Pepys broadside can be seen at  The Pepys Ballads:

The Wandring Maiden, Or, True Love at length United,  

Related texts and commentary are at Bruce Olson's web site, archived at both the Mudcat and the University of Fresno:

http://www.csufresno.edu/folklore/Olson/SONGTXT1.HTM#BYSKLKN

http://www.mudcat.org/olson/viewpage.cfm?theurl=SONGTXT1.html#BYSKLKN

The tune for 'Over Hills and High Mountains' seems not to have survived.