Stunning plough plane from a very respected maker...Isaac Sorby. The "Punch" trademark was introduced in the late 1800s....around 1870 if I remember correctly....but the history of Sorby is very confused....there were loads of family trees compounded by the fact they all seemed to make tools or cutlery!
I think that this is the trade mark moved over to Turner, Naylor and Marples...so yours could be anywhere between the end of the Victorian era and early Edwardian period up to 1920...though I suspect this fine example is around the turn of the century.
Screw type fence adjustment is more sought after than the simple wedge arrangement and generally it is best to keep the irons that came with your tool together with the tool as they are matched. Don't try to flatten the backs...they have a natural arc which forms part of the locking of the iron onto the sled using the wedge for pressure. Sharpen only with one bevel too. A secondary bevel is not used and will affect the performance.
The sled is particularly nice...the curve at the end is lovely!
I would use a light coating of boiled linseed oil on it and then repeat every so often to feed the wood. Don't soak it in linseed oil...this is not required.
Lovely plane... =D>
Jim
