Is This A Precancel?

There are about six precancels that look VERY much like this one but they do not appear on the 10c plum shade of the Admirals. There are also two other similar precancels that do appear on this stamp. One of them has ONTARIO written out in full instead of the abbreviation and only has two lines in the middle. The second one has letters like your stamp but only two lines in the middle and these lines also show smaller waves or arcs on them.

Thanks, Scottamer - that would account for the huge variation in prices I've seen for some of the Admirals.

By the way, do you happen to know if any of the Admirals were printed on coloured paper? (I have one that is on distinctly greenish paper.)