G'day Nutmeg,
this is an US "Duplex" cancellation
(a two section cancel Circular Date Stamp and "killer No25")
Yours is the first ever I have seen with "25"
I have examples of 1,2,4,6,11,14,19, mute,"P" and "RMS"
example of nought (belonging to a member here)
I refer to the barred section as a "footprint" style

Here is an example of an 8 barred "4"
Others here may confirm, but I think the number just refers to
the cancelling station along the counter of the Post Office,
but I am not sure.
