caught myself in a lie.. should be checkin more before typing
using the SSH -X tag for secure shell works just fine so long as you use that argument on both hops.
Remote Pc ----(ssh -X)----> External PC ------(ssh -X)----> internal PC
Works!
Remote Pc -----(ssh)------> External PC -------(ssh -X)------> internal PC
No good!
So long as you carry the -X argument through all your hops it looks like there is no problems forwarding GUI. I'm sure I could have read that somewhere but nothing beats an actually test.
Looks like I got this in the bag. Thanks!