Should have more than a one hundred years these tongue and groove planes. I picked up them from ebay, maybe they come from Austria or Germany. No marks on the plane body, neither on the blades.
They cut a 8 mm tongue and groove.
The main problem was that the wooden screws was blocked into the body and for two of them I cannot unscrew. The only solution was sawing the plane body for reach the thread and release the screw.
The damage was inevitable and a repair needed!
I dislike to have these tools only for collecting them; I love to use them too. So I attempted to a structural and functional recovery, preserving, if possible, their lived-in look with some sign of aging
After washing with soap and treated with an anti-worm product (although the old holes seemed empty), blades and steel skates received a anti-rust treatment.
The pieces were then re-glued and veneers were used for closing the saw grooves.
Then I closed the worm holes, leaving some intentionally.
The functional recovery concerned after all in to steady contact points (soles and fences). For this job I used mahogany strips. This wood is also present in the wedges and regulating screws.
The skate bed and sides were rectified by a big file and by sliding the plow on the abrasive paper while keeping it square.
The two half-skates are inserted into a groove of plane body. At heel ant toe, the skates have dovetail shape and are firmly held by a nail driven into the body.
One wooden screw has split while removing it and I had to repair by gluing.
Blades are hand forged; the plow plane blade was worn-out, so I had to substitute it.
I started from a 32 mm single plane iron, cut by a angle grinder (cooling often) and refinished at bench grinder. 
By looking at old blade, it shows a trapezoidal section and slightly tapered sides; this avoids the cutter binds into the groove walls, even if the plane rocks a bit.
Moreover, the original blades show a convex shape for a stronger holding of them by wedge; I imitate this for the new blade and it works.
