Just to chime in, late to the party to be sure, I absolutely LOATH the Global Shipping Program and Pitney Bowes especially with UK items bound for the US: even on their best behavior, I've found them expensive, slow, unreliable, careless and totally uninformed about (as well as completely indifferent to) the nature of whatever goods are entrusted to them to needlessly repackage and convey.
Others' mileage may vary, i am sure. But in my experience they've a hair trigger for flagging all manner of vintage objects as "prohibited." And although they maintain otherwise--to the unhappy pair of buyer and seller concerned--after a "confiscation" they frequently sell valuable objects to some local job lot outfit they favor, and voila!, the object gets listed again by this new seller, 2-6 months later (as often as not using much of the same descriptive prose as the original seller did). Ironically, many of these sellers don't use global shipping themselves, but some other private courier service.
Another intensely annoying issue is that Ebay UK conceals from the seller what exorbitant postage fee appears to potential US buyers, while US buyers see no obvious red flags to indicate a listing will be shipped via GSP. My own practice now--with anything unique I strongly want-- is to WRITE to the seller while an item is still active to explain my own wretched past experience with GSP, and ask if they're willing to use Royal Mail or some other service to post the object to me in the US DIRECTLY. Many will do so. And some are absolutely floored to know what shipping fee is displayed to potential US buyers.
As for the purloined silver mounted Susskind Bros pipe, be vigilant, Ashdigger! 50/50 chance it will appear again on eBay UK by early autumn, offered at much the same starting or buy-it-now price. I know last year I and a UK seller exchanged emails for months after a 19th century bottle of Floris (still sealed and half filled with essential oil) was confiscated and disappeared into the Pitney Bowes maw. Then, miraculously, there it was--using her photos. And now it is sitting on my shelf (after sailing through customs without issue).
Just saying.