The Crescents were pretty darn good guns! My wife has a 16-gauge sidelock that's a "genuine" Crescent, marked that way.
I'm also an admirer of Spanish side-by-sides, but AyA's have gone up considerably in price, even used boxlocks, having been "discovered" by shotgun loonies in the past couple decades. Better bargains these days are the less-known makers, especially those who went out of business due to the Diarm deal. My 10-gauge is a very nice Armas Erbi I picked up for such a low price I was almost (though not quite) embarrassed about the deal.
