..."'Krenov style' - laminated from three pieces" this sound interesting.
Four pieces actually, since you cut the center on in two. Take a piece of stock of the appropriate thickness and length, and two saw kerfs wider than the finished plane will be. BTW, for a tighter mouth, make the new block just a tad thicker than the original, then when you've reassembled it, you can carefully plane the sole to get a tight mouth.
Slice off two pieces - one from each side - to be the 'cheeks' of the new plane.
Cut the middle piece, at the appropriate place, at the proper angle - probably 45° in this case, since that's what the metal frog is set at.
For the nose piece of the center, cut it at maybe 95° or so to allow for shaving clearance.
Glue everything back together in the appropriate shape, install the metal, and you've got yourself a new plane.
-------------------------------------------------
Another way of doing it - using the original plane body - would be to laminate a whole new sole onto it. Just glue a maybe quarter inch thick piece of hard stuff onto the sole and then carefully cut a new mouth through the new sole.
Have fun!