Need the help of an expert urgently

I just found in the used jewellery market a sublime square 222 18k YG and SS. But there is no Vacheron Constantin in the neighbourhood. Is ther any fast way to confirm its authenticity ??? (knowing the gold is real),I apreciate any  helpful advise.
very hard without at least case and movement numbers or a scan (nt)
07/29/2009 - 11:35