One is 245mm long and the other is 235mm and 3/8 inch wide and the other 1/2".The end taper goes from 17mm up to 21mm radius, and other has 4 studs on the taper.
Talks in advance to who identifies them
Almost certainly from a "Thumper mortice machine" bit held in place, timber secured in a compound " X -Y " Vice, you brought the handle down with a bit of force, a few drilled pilot holes started you off, then came the motorised version with the hollow chisel and an internal bit, the bit rotating-drilling the bulk out and the stationary square chisel cutting the hole parallel and square.
In the seventies the company I worked for had a "thumper morticer" standing in the corner, and I nearly acquired it, but it was quite big and a cast iron brute, I had a few goes, but as you would expect we had an electric Wadkin.it was still in the corner looking quite sorry with surface rust in the early 80s when I left. Business is finished now, bet it hit the scrap yard. did every thing a modern day electric hollow chisel machine does. Guessing this machine by Howkins pre dated our cast iron version The chisels bear an uncanny resemblance to the heavy hand mortice chisels I have stood at a bench and knocked holes into window frames doors and door frames- happy days
Cool Stan they do look like a very efficent piece of kit.Ive just been browsing the Internet if anyone needs them or collects them, anyway i came across this too.http://old-woodworking-tools.com/index/pages/158.htm