Here's a slightly odd one, coming up in the Gavin Gardiner auction on 5 October: a .375 Rimless double rifle made by Arrieta. With the current near parity of the £/ $, this is a potentially good deal for an American reader.
https://www.invaluable.com/auction-...prod&queryID=07dafab433f3c2e0e1b991fe1b995033
Note that one barrel in the photograph reads 'SHOT AND REGULATED BY', and I suspect that the other barrel reads 'HOLLAND AND HOLLAND', putting it into the late 80s/ early 90s, when Holland and Holland were using this phrase on third party rifles that they were selling on (before they were taken over by Chanel and moved up-market). Potentially, given that the engraving is in the house style, they might have done the engraving as well (not that that particularly adds anything). The .375 rimless is the same round used in bolt action rifles, ie. not the rarer .375 flanged which would be the more obvious round for a double rifle, and which means that the rifle presumably uses detents in the ejector mechanism (one more thing to go wrong).
Great as it is, is the .375 really a double rifle calibre? On the other hand, there might just be someone out there hankering after a .375 double rifle - a Scandinavian going after moose, perhaps - and here is a good example of a well-built rifle built on London lines but without the cachet of a London name. If you are just about to pay the deposit on a German rifle, I'd pause for thought. It is fully valued - to my mind at least - at its estimate, so not really a 'good gun deal this week', but the advantage of an auction is that one might just get a bargain.
NB always ask for condition report. My close inspection of the photograph shows a strange keyhole-shaped cut (?) in the right fence which might be worth getting to the bottom of.