Jamie... just found this, which may be the answer to your question regarding links between Peddlar's Way, Icknield Way and Norwich.

http://www2.cmp.uea.ac.uk/Research/researchareas/JWMP/CaistorRomanTown/crtp4.html

Didn't make it as far as Holme this weekend (will try again next week when there's more daylight!), but did find Holkham Camp after a bit of searching.... it's a beauty too!