Bluish Paper Cover Eval + Orange Bg Question

This is probably a silly question, but when checking for bluish paper with an orange background, could the orange be digitally applied after using a background remover to get the same effect? Or does the stamp have to be physically sitting on top of orange paper?

I ask because I think this might be worth the cost for submission as 361 on cover, but I don't want to soak it off to examine the back if I don't have to. The condition of the paper is still fresh, and there aren't any signs of plate-wiping (excessive).. so the grayish color can be viewed quite nicely, or without much assumption that the stamp had just been weathered poorly.

Another double-line 335 will sit next to it in the last picture.






If digitally applying an orange BG can be just as useful, I'll happily purchase the software needed and post the results.

As you did with the 335, you can place orange paper next to the stamp.

As to certification, it will be two steps for a good cert; first a review as is, and second, if needed, is to remove the stamp and resubmitting for verification of proper watermark status.

An often not mentioned route is to buy one of the less expensive blue papers with a certificate as your home reference.

Excellent advice PPG. Buying a certified copy would certainly be a smart choice before submission.
Is it absolutely necessary for them to remove the stamp to make a decision?
I found some orange paper and did a cutout as you suggested: