Peter Powell kite stickers - a possible timeline

If you're familiar with Peter Powell Stunters, you will be familiar with the stickers that adorn the sails of the Mk I Stunters. But what you may not realise is that there were several versions of these stickers over time ...

Curious how many versions actually existed, and whether you could use them to 'date' PP Stunters, I set about gathering pictures of these stickers, from my own collection, and from photos of PP Stunters available on the internet. Focusing purely on UK-produced Mk I Stunters, I have so far been able to find six different versions. Not saying more don't exist, but these are the six I've been able to find so far:

So is there any way to order these six chronologically, from earliest to latest, as that would offer a way to date Mk I Stunters, at least relatively? Well, none of the stickers has a date on them, so that doesn't work; we'll need to use a bit more subtle detective work ...

First of all, two of the six stickers I have seen only on aluminium-framed Stunters, and we know that aluminium frames predated fibreglass frames. So those two must have been used in the early days. But which is the older of the two? As I said, they don't carry dates, but I think I've found a clue to help me order these two, as well as the other four, chronologically.

I'll tell you what that clue is a bit later, but let me first show you what I think is the older of the two stickers on aluminium-framed sails (and therefore, the oldest sticker I'm aware of):

And the, in my opinion, younger of the two stickers on aluminium-framed sails:

So that then brings me to the stickers from fibreglass-framed sails. And to revealing the clue I've been focusing on: telephone numbers. The phone numbers on these two early stickers are 0242 30922 and 0242 88411. Only one of these numbers also appears on two of the stickers from fibreglass-framed kites: 0242 30922. On the assumption that Peter didn't change his telephone number back and forth, I concluded that the sticker with the 0242 88411 number must be the older one. 

As I said, two stickers with the 0242 30922 number, and I struggled with relative dating of these two, but here's my best guess. Older of the two, I think, is:

and the younger of these two, I think, is:

My reason for thinking this the younger of the two is that it is more similar in design to the next one, which has two clues to it being later:

So what are these two clues? First of all, the phone number has changed, to 0242 43222. And, secondly, it has added the 'toy of the year award'. And that allows us to pin this one down to 1976. So the stickers up to this one must date prior to that award.

Which leaves me with one final sticker, and my reason for thinking this the latest of the six is, once again, the phone number:

Design is quite different from the others, gone is the 4-stack with tails and the 'toy of the year award', but look at the phone number: 0242 862650. One digit more than the others, which suggest that this must have come when phone numbers in the UK were updated to include an extra digit, in order to increase capacity.

My timeline is mostly based on phone numbers, with a bit of gut feeling thrown in. So I may well be barking up a completely wrong tree. If that is the case, and anyone has any information to improve or outright reject this timeline, please let me know, so we can update this post and firm up the timeline. And if anyone is aware of additional versions of stickers on UK-produced Mk I Stunters, please get in touch.