Yes, thanks -- it turned up the very next day (i.e. yesterday). Happy result.
Sent in the bond forms together with the EPA certified copy, on 20 Jan.
Bond purchases confirmed OK in letters dated 31 Jan and 02 Feb.
Then my EPA certified copy came back in a letter dated 28 Feb (saying, "For your convenience, we are returning it without delay on the assumption that you might need to present it to other organisations").
They processed everything trouble-free even though we'd used the regular application form for the bonds rather than the Attorney form (which I think wasn't openly visible on their web site at that time).
Satisfied customer!
So, returning to the original question:
I am a bit put off by having to enclose a certified original copy of the POA.
Has anyone else successfully done this and had it safely returned?
I can now say: Yes.
(As always, make sure it's the certified copy you send, not the original.)