For me it'd be any really good quality British (not necessarily English) double in .500 and with as short a set of barrels as possible. I don't care about it's accuracy at 100 yards but rather at 5 or 10 yards.

Action type would ideally be round action or rising bite but I could be flexible on that without any problems.

I tend to like old classics in guns, cars and motorcycles that preferably have a bit of interesting history but would be more than happy with a new double rifle..... esp if it came from an interesting manufacturer.

As far as engraving is concerned, I'd rather have something traditional such as rose and scroll and/or limited engraving rather than badly done animals.... well done animals are fine but I'd have thought there's very people who can do that kind of work nowadays.... might be wrong though.

My ideal sights would be simple shallow vee on a quarter rib at the back and the untraditional (is there such a word?) but very effective red fibre optic foresight at the front.

If I had a choice between ejectors and extractors, I'd choose ejectors.

Nice to dream for a few minutes!