A lot of the old razors I have and have seen are not what you would call "evenly ground" on the spine from manufacture. I found grinding the spine evenly, very easy. The honing wear gives a very good guide and it's not that I am advocating the complete removal of the existing hone wear. Just to grind the spine till the wear is an even line and to what ever width seems appropriate.
I came to this idea mainly because I think that grinding the blade actually changes the geometry of the honing angle to some extent and this method retains the existing angle. Not that I consider the angle on any razor to be a pre-set, hard and fast set of degrees, just an approximate. I just consider the old wear pattern to be intrinsic to the razor.
I have some reground razors done in the conventional sense, and they now do not carry an even hone wear to the cutting bevel or the spine. This "wobbly" blade grinding is more likely to produce uneven hone wear than the method I put to you. ( the regrinds were done by a well known regrind specialist) If a razor is so worn that the cutting edge is too think, then the blade grind is the only option, this I concede.

PuFF