Offset problem...

I did a little bit more on my Frame Saw last night and it seems to be coming along quite well. On the face of it, this is a pretty simple project...just three bits of wood and a couple of turned handles, but there's a bit more to it. The design is based on the Continental pattern that can be found here at DICK in Germany and is what I've modelled my one on. You can make them very plain but I decided to do a bit of shaping on the ash sections so I made up a template from some hard board and drew out the shapes on the ash, cut them out on the bandsaw and did a bit of shaping with 'shaves and a cabinet rasp. I've also included a large rosewood loose tenon (in fact, both tenons have to be loose 'cos the frame pivots when the pressure is applied to the blade) which I've seen in some designs, in theory to prevent the frame from twisting.
I've got to do the handles next with the carrier plates for the blade (these link the blade to the handle)
The problem that I've been pondering over though is how to ensure that the blade is centrally in line with the handles? The blade is joined to the plate by a nut and bolt so some bit of it is going to be offset...if the plate is central, the blade will be offset by the thickness of the carrier plate. The answer, of course, is simple and anyone with a reasonable amount of 'grey matter' would figure it out much sooner than I did...I need to offset the slot in the handle for the carrier plate by the thickness of the saw blade.

Simples!