Beautiful Cumberland Tuscon, They are my favorite Dunhill's by far and one day i will own one. The one Dunhill i have, a 1975 Root Briar 511 apple, came with some (not aforementioned by the seller until i received the pipe and contacted him) spider webbing inside the chamber of the bowl. After speaking with the seller as well as one of the pipe experts at my local b&m and showing it to him personally, they both said the same thing in that it would be fine and no problem at all. They said to just smoke slow for 10 to 15 bowls and build a cake over the webbing and it should be fine. Well, that was over 6 months ago and i've put a lot more bowls through it than that and it still smokes like a champ and they were both right, it hasn't affected anything at all. The webbing is caked over now and it is a wonderful pipe with no issues.
If/when i do sell the pipe though, i will put the spider webbing that is there in the description. I thought it was kind of shady that the seller didn't include that in the description and did not show detailed enough pics so you could tell. And it was obvious that they were there, as soon as i inspected the bowl i noticed. Honestly, i probably wouldn't have bid on it if it was apparent from the pics and included in the description. A seller might get away with that shit for a while, but eventually they are going to get called out and have a tarnish on their reputation.
Anyways, sorry for the rant and derail, congrats on that beauty and i wish you many many many great smokes from it!