Differences between the Australian subspecies of the Yellow-billed Kingfisher and those of New Guinea

Hello All,
Recently I did a trip to Iron Range with Ken Haines and Ken spotted and
photographed a female Yellow-billed Kingfisher. When we got back, I put a
request in birding-aus for details of someone on a 2012 trip with Klaus
Uhlenhut, where we saw a male Yellow-billed Kingfisher. Robin Irwin, who
was on that trip kindly sent me some photos and this got interested in what
the differences might be with those Yellow-billed Kingfishers found in the
New Guinea region. Our Australian one is a subspecies. It seems that
there are 2 or 3 other subspecies in New Guinea.
I don’t have a copy of Phil Gregory’s New Guinea Field Guide, although I
may get one for Christmas. Does anyone know from personal experience if
there are any noticeable differences?
I imagine that there may be some of this list that might know, Phil Gregory
or Geoff Jones for example but there might be a few lucky others that have
been to the New Guinea region too.
Best wishes,
Patrick Scully