There's not much to go on, besides this thread from a year ago. I don't think participants in this thread made the purchase. Mike Lankton bought one, from memory and I believe he was pleased. Mike had the "CakeandDottle.com" page, but that is now defunct.
All I can say is that I used to have an Invicta marked Hand Made by Colin Fromm. If the pipedia quote I cited in the other thread is correct, it was before Castleford. I've seen other Invicta's with the marking. The one I had was a really nice pipe, shouldn't have sold it, but needs must.
Colin Fromm worked with Colin Leeson at Invicta Briars based in "The old ragged School" in Chatham. Originally starting out as a repair shop, they began producing their own pipes under the Invicta label. They also produced pipes and did stem work, for other companies. I've seen trays of pipes in the factory that were destined to become Charatan's and Astley's . And repairs for Dunhill.
The Castleford brand was created by Colin Fromm with a view towards the export markets .
Colin Leeson sold the factory to Dunhill and Colin Fromm transferred over to Dunhill. Part of the deal was that Colin Fromm was to be allowed to continue his Castleford brand ( I think the brand has now been retired ).
Colin Fromm still does Dunhill repairs and produces the Dunhill HT pipes and some (all?)of the high grade Charatans.
Back in the day, it was always great to pop into the factory. Repairs were done while you waited and new pipes were always available for purchase.If there was nothing that took your eye, Colin Fromm would make it for you - it would only take a few weeks.He could also copy pipes, and made me a straight grain copy of a large Ferndown bent apple bark.
Visitors to the factory are no longer allowed