Jim has a job indeed.
I know lots of people assume that the "wooden bit" of infill planes is the easy part ... I have just spent the best part of today putting the front bun into Jim's plane's little brother, a smoother I made before with the same shaped Cupid Bow.
Fitting is one thing; I've done that before but today I drilled for the bars to hold it in.
In the drill press, on it's side, in the machine vice, clamped by the sole to the jaw of the vice so as the drill bit would be parallel; I drilled the two holes. Then, with the infill in, drilled the wood through the holes in the steel and spotted the inside of the other side, took the wood out and continued through both holes in the plane now able to suds the drill. All well and good - couldn't have been more accurate. I put it all together and the holes in the infill were about half a hole out from those in the other side. #-o
So I had to cut two short 6mm bars, put them in the side that lined up half way, clamp it all together again and drill through the off holes in the steel, opening up the duff half of the holes in the wood. With a bit of tapering on the ends they came through ok with some persuasion and no lifting of the wood.
I'm sure you will be able to do better with the milling machine Jim but it's been a bit of an off - putter for me as to using sleeves - 1) It wouldn't have been possible and 2) it is quite immovable without them, think of draw pins .... :shock: