Apologies if this has already come up, but have limited internet access here in Portugal...15 ac: "I near Eastern end of Borneo with no guidebook" (4,5) e--- r-n-y
and 9dn: "Establishment hoping for a pot og gold at the end of the rainbow?" (5,4)
t---t -a-m
Finally, 54ac, "Turned gas on with...this?" (5)
s---w
Many thanks to whoever can help; found this puzzle really difficult and not in line with my thinking...