Information On 1935 Cover Please

Here's another item that I'm not sure of, I just can't seem to find where the 2 cent postal note is listed.
Is there any thing interesting on this cover?
Seems like there's three types of stamps and the cancel on the postage due stamps is different then the one on the back of the cover.
Is this all normal?

Cheers, Bill

At that time, the basic letter rate was 2 cents, plus 1 cent for the war tax. If you short paid the postage, the penalty was double the amount of underpayment. The postal note stamp wasn't valid for postage, so this letter was 2c short and thus, a 4c penalty was assessed.

The postmark on the back notes receipt of the letter in Pickering. (The postage due stamps were also applied in Pickering.)

Canadian postal note stamps are listed in The Canadian Revenue Stamp Catalogue, E.S.J Van Dam.

This is an attempted use of a non-postage stamp for postage. It was not cancelled for that reason. Postal note stamps are explained here:
http://www.bnaps.org/ore/Ryan-Reven...stalNote.htm

Short 2c actual postage, as Cjd said, this was charged double the amount needed, as normal, with the postage dues added and cancelled on receipt at Pickering, as expected. The Pickering cancel on the back was struck as normal on receipt but the postage due stamps were added and cancelled by another/others.

This was properly handled and "normal" in that sense. It is an interesting postage due cover but it is probably a (fraudulent) attempt to get the postal note stamp past the post office, so perhaps done by a collector. This is not a rarity; probably somewhere around a $10 cover.