Yes, let's get
MauriceMoss on this one!
Aside from the cut-outs in the sockets of the BB shell (new to me) and the internal routing in the chainstay (rarely seen) the "fishmouth" stay end to DOs are important clues IMO.
likewise to judge build timeframe the portacatena holes but is this frame/fork intended for nutted style brakes?
Once had full chrome for a cromovelato finish I reckon