This one is a Type 19, made between
1958 – 1962, Most likely 1962.
Type 20 arrived in 1962 and saw the change in enamel colours from Black
to Blue but this plane has none of the manufacturing changes of the Type
20 and therfore must be assumed to be a Type 19 with blue enamel.

The No.5¼ is 11 ½" long and has a 1 ¾" cutter. It has dark stained
hardwood handle and knob.
Being somewhat smaller and lighter than the No.5, these planes were initially
intended for use in schools. (Remember when woodwork was part of the national
curriculum?).

These pics show the difference in lengths between the No.5 ¼ and the No.5.
The
next pic shows the difference in widths.

The No.5¼ and No.5 side by side, toe view.

The No.5 ¼ is a great plane for fitting in the tool box when travelling to jobs as it takes up
less room and of course weighs less than a No.5 and it does an adequate job as a jack plane.
At the top is a standard No.5, middle is a Type 20 No.5 ¼ whilst a No.4
is at the bottom of the picture.
All of the 5 ¼s I have seen come from the USA. I don’t know
if they were ever produced in Sheffield.
I’m sure someone out there in
Planeland will be able to tell me.