I've had this kind of blade width difference on several older blades I've acquired from EBay. Some are wider at the toe, but most are wider at the heel.

What I've done is just place a piece of 400 or 600 grit wet-dry sandpaper on a plate of glass and use the marker test to determine when I've honed it down to where the entire bevel is making contact with the surface. Then I just hop on my DMT E (1200 grit) and continue my normal progression. This sometimes results in a little more hone wear than I would ideally have, but it works. You could probably lessen the extent of the hone wear caused by this kind of bevel setting by wrapping a piece of sandpaper around the spine and hand-sanding, and then reset the bevel, but I haven't really felt the need to do so.

DISCLAIMER: I am not necessarily what you would call an expert like Glen, or Max, or any of the others around here who carry that reputation. I have restored at least a dozen old, cruddy EBay razors to working condition, but not to a "showcase" finish like those done by the above-mentioned experts. I'm just saying what has worked for me.