Great Britain - KeVII Plate Number Question

I am trying to figure out if I can used a plate number to identify a Great Britian KEVII 1d printing by the Stanley Gibbons catalogue.

I think plate 19 is probably a later printing and may be one of the Perf 14 Harrison printings - possibly SG 273 - 1d Deep Rose-Red, but maybe it is just SG 220 - 1d Bright Scarlet.

Any opinions? Thanks

Never answered before.

No, you cannot use the plate number to identify it as it is not a plate number and yes, the number 9 is the year in which it was printed. Consequently, you can identify the printer.

This is not a plate number, but a control number. The 9 identifies it as printed in 1909, so it is a De La Rue stamp.

The control letter I was the second used in 1909. This was introduced near the end of the first quarter of the year. The control was reported as early as October 1909.

It is either SG219 or SG220.