[quote author="sintech"]You see vintage Neve 31267's for sale in the black market quite frequently, they also can be wired backwards to emulate the 10486.[/quote]
Not exactly! You're only using one of the two coils in that case, so there is no noise cancelation. That shield can is almost useless in this regard and the hum pickup will be unacceptable if you have a mains transformer nearby. Also, the line input transformers (31267 and 10368) seem to have higher DCR than the mic input (10468) and therefore will cause more loss. Some microphones (read: passive ribbons) cannot drive this properly. Granted, I do not recommend this option. 10368 wired forwards for 1k2:2k4 works great with high output condensers and dynamic mics on loud sources, but the ribbon mics are still a problem. It also doesn't sound quite like a 10468. Darker, more lows.
Should you chose to ignore my advice, 31267s are readily available on eBay via www.danalexanderaudio.com, available from him directly, or also here http://www.technicalaudio.com/sconebar/