OWD,
You're absolutely right about some the guns that were never offered/sold to the US.
Like this pair of AYA "Senior" #1s (available as self-openers or standard). These were built on a Beesley type action with tight Purdey-style scroll (normal #1 models are built on H&H actions). Ugartechea also offered a Beesley sidelock.
This a copy of a Purdey hammer gun from Ugartechea (Model 1021).
Or this express rifle from Victor Sarasqueta
And another...
Another offering from V. Sarasqueta.... a Woodward sidelock over/under.
