2d blue faked to look like an 1840 issue?

I believe this is a Plate 4 2d blue, with the white bars inked over to look like the first issues of 1840.  I'd welcome your thoughts:



There are lots of tipoffs, to my eyes:
The white lines, especially the one above TWO PENCE, are still apparent;
The cancel is late and would be exceedingly rare on an 1840 issue;
The check letters do not match images of Plates 1 and 2;
The A looks to be blind, and the D looks to be broad, both of which are characteristics of Plate 4 versus Plate 3.

Is that what I have?

Thanks for looking.

C.