I think I can make a guess at the date. That light blue wrap appears for one or two years around 1962-63. Ajax it would seem used a darker blue wrap before 62 (seen that but no photo to show) and it would appear had a shipment of light blue which they used as I say for 1 or two years. The lighter wrap was used for English Rogers and other Ajax production. This is English Rogers -
[IMG]http://i207.photobucket.com/albums/bb77/nutbox/1e39_11.jpg[/IMG]
Not mine, just a photo I saved out of interest.
This too is English Rogers and shows the contrast between the two blues .............
[IMG]http://i207.photobucket.com/albums/bb77/nutbox/7c44_11.jpg[/IMG]
I have seen Strafford by Besson in that lighter blue as well.
If there is a serial in that snare I would expect it to be in the range 68*** to 80***.
That's me out on a limb!