I paint the iron with lay out dye or a magic marker, then scribe it to the sole to get a matching profile. This is the part I've got a lot of trouble with, as I've never made a right angle scriber to do it right. It also assumes the sole is consistent, which is not always the case. I made a little jig to hold the handpiece of a Foredom tool at 30 degrees for grinding the concave bevels. Its still slow, but quicker than using just a slipstone.
With this particular plane, the bead part of the profile is only 3/8" or so, and too tight to get the scribe from my square in there. Also the plane appears to be shop made, and has no spring, so the mouth is not consistent, making a little scribe with the ball on the end rather in-accurate. This one was pretty close though, so I used a coarse slip and trial and error to get it right (or close enough to use for a while in this case).
Thanks for having a look,
John