p.s. i cant use "trap" for some odd reason.
Trap is only active in CMYK mode, and it's not the same as bleed. Bleed is simply printing larger than the final size so that when trimmed, image is for sure borderless.
Unfortunately, you can't simply make one side of the page larger, without "warping" the image.
Can you possibly do this?:
Use Image/Image Size.
Check Contrain Proportions.
Leave at same PPI you have now, change the problem side to 5.25. The other side will grow (and the whole image will upsample some, but assuming you already have around 300ppi?, shouldn't matter much).
Only question is, will the info that's on the other dimension still be there when trimmed to the dimensions you now have?
Only other thing I could think to do is "cheat" the one dimension by adding canvas size to make the 5.25 on the one dimension only. Then you'd have to clone what's on the edges on over the extended area. Glancing at your images, this might be doable.
Mac