The experience here on RCTW with Toucan Hobby (and there are other names used on eBay, but all are related to Toucan) has been mixed. Here in the US over the past 8 or 10 years, I have ordered a few tanks and other items from Toucan and have had no problems with shipping at all. I see that you ordered the barrel with recoil for your Challenger; I did the same for the T-72. I will be watching for explanation of how to switch out the barrels. No hurry, I may be among the more patient here on RCTW because I need to be: I am NOT among the most skilled.
A+++++ for Toucan. The eBay vendor I used for Toucan was "I Love Porcelain Flower" which sounds more like a vendor of other electronic "items". At the bottom of their listings they say if you need something they don't list, just ask. So I did. Requested a HL KVII turret only, and after several back and forths to make sure it was what I wanted, out it went. Cool part was that the price I was quoted was too high for my budget, so they asked what would be my target price and they agreed to it. And I asked for a price drop of $45CAD!
I have had good service from Toucon/Porcelain Flower/Color Never Fade. Initially I was suspicious because of the flood of eBay listings, but I have ordered a few directly and done fine--including the barrel for the T-72 ERA.