Any question answered...

More than that, it's 590mm. That would mean a 15.5mm difference, can your calipers handle that range?
You can still get quality rims and tires in that size (Sun CR18/Panaracer Col de la Vie), would look best to keep the same size.

sjs list them

http://www.sjscycles.co.uk/rims-26-%28590%29-dept168_pg1/