When the Country definitives were reprinted with white borders in October 2003 there were some major changes from the previous 'all-over' designs.
Originally the Northern Ireland stamps had the face value and Queen's head in white (that is, they were 'reversed-out' of the colours - unprinted space) whilst all the others were silver. For the version with white borders the Wales stamps changed from silver to white/reversed-out.
In the case of the England stamps only the format of the Queen's head also changed, and this is known as a Type 2 head, the previous one being Type 1. I can think of no real reason why the England stamps should change while the Scotland silver heads stayed the same when they are printed by the same printer.
When postage rates increased in 2005 there was doubt that De La Rue would be able to print the 42p country stamps to the required deadline, and the job was given to Walsall Security Print. Their stamps were released on 5 April.
The De La Rue versions of the same stamps were issued on 10 May and 26 July (Northern Ireland). As soon as they were received dealers and collectors made efforts to identify differences and they were immediately obvious on all four values.
On the England 42p the main difference was the positioning of the figure of value:
On the Wales stamp, the Queen's head was smaller on the De La Rue printing (as were the figures of value), but the ribbon show this to be Type 1, and quite different to the head on both versions of the England stamp:
See more differences here.
When the 44p and 72p values were issued in March 2006 they followed the same pattern. England stamps had type 2 heads and the others had type 1. And there the story ought to have ended.
Except that all the England values have also been found with Type 1 head. Some sources say that these arise from late 2005 to mid 2006 reprints but a print date of 10/7/07 is stated to exist for the 72p. Why this should be so is hard to understand, as the 78p value was issued in March 2007! I suspect this is actually 10/7/06.
Because of the silver ink it is easy to 'see' many minor variations in the head with its intricate curves and features. But when you find an actual Type 1, it is quite obvious, especially in this digitally enhanced image:
The ribbon is the most obvious feature. The top of the head in the top picture has an extra wave in the hair, and there is less detail between the nose and the chin.
And the two types exist on all four values - 2nd class, 1st class, 44p, 72p. Subsequent rate increases produced the 48, 50p, 56p, 60p, 78p, 81p, 90p & 97p all with Type 1 heads.
The 2nd class and 1st class are, of course, available at normal prices as the reprints continued to have Type 1. The 44p and 72p Type 1 are very scarce. Those distributed by Royal Mail on standing order will be Type 2. It isn't even clear whether the Bureau had the type 1 printing of these values or if they were distributed only to Post Offices. In any case, it is well worth looking at used copies - these differences ought to warrant full listing in Stanley Gibbons GB Concise catalogue in the same way that the Type 2 regional definitives of 1986/87 do.
The Northern Ireland 17p and the Scotland 31p Type II are both catalogued at over £100 used!
The moral of the story is that it may well be worth looking closely when you get any new versions of stamps that have been reprinted many times. Time to dig out the 30x magnifier or get the scanner working. We looked closely at the 42p, but few people would have looked carefully at later issues. And when it comes to country stamps, it's always worth buying some at post offices as well as from the Bureau. If they are the same, you can always use them for postage!