A belated thanks for the advice, Jaybo. Just to end this old thread stump, the Concertos were not in good condition and the sound quality didn't suit my taste at all for use in a small room at close range. I used a pair of minty-new Quad 12L passives at the shop just as a comparator, and as they were very cheap for the sound quality I got those and I'm very happy with them as temporaries and for the price. Very warm and clear speakers, wide and deep imaging, with really decent bass on my desktop, and with the wood finish they've got huge WAF.
I've got them on trial for a month, and I'm still considering replacing them with Adam a7 monitors, which I've heard in a display room but cannot home trial first. They are amazingly clear, but with their utilitarian appearance they seem to have very bad WAF.
Of those on your list, some seem hard to find here in Japan, but I've put my name on some lists for used SF Minimas, in case some appear.