I have a set of concentric punches, made en France by 'Mekano, ref: 450bis. Unfortunately I do not speak French so I'll describe this set and give the French details from the printed label in the tin.
1. Main Punch with two concentric spring-loaded and one central screw-in positions for the various cutters.
2. Large Cutter heads - 30mm. 28mm, 26mm. 24mm, 22mm. for pushing on the larger part of the Punch
3. Medium Cutter Heads - 20mm. 18mm. 16mm. 14mm. 12mm for pushing on the smaller part of the Punch
4. Small Cutter Heads - 10mm. 8mm. 6mm. 4mm. 3mm. for screwing into the smallest part of the Punch
Any two different-fit (Large, Medium, Small) Cutter Head can be mounted, concentrically, on the Punch at the same time.
The largest 30mm. Cutter Head lives on the Punch in its red hinged tin container which is lined with a profiled red plastic base.
Now what it says on the Label:
Mekano printed to fit in an elongated diamond. Must be their Trade Mark. Reference 450 bis. Fabrication Francaise. Marques, Modeles et Composition Deposes. Decoupoir Mekano No.1 Bis. Brevete S.G.D.C. Pour Rondelles ou Joints de 3 a 30 mm. Decoupe Toutes Matieres pour Joints: Guir, Caoutchouc, Carton, Fibre, Amiante, Plomb, etc. Cost me £20.12p. inc VAT from my local Farmers Equipment shop (where they also sell Tractors and nuts & bolts, glue &c., and service petrol driven lawn-mowers.
That's all, folks!
Michael UK