Thanks Carson, I'll look for it this weekend. On your suggestion about the regeneration valve; is that the same as the Purge control valve? If so, then yes, I was considering it, but I was going by this post from Gilly:
HELP! 1997 E-420 P0455 EVAP Leak
Excerpt
"I'd say if you want to "throw a part" at the problem, with about 75% probability the shut-off valve is the problem."
I don't have the test tools he mentioned, so I was going to try his advice. What do you think?
Don