Just to put a lid on this for you... received my reply from Avon today... as I thought the details were as I mentioned for the tyre...
Starts/
Vowles, Ashley. <AVowles@coopertire.com>
11:51 (19 minutes ago)
Hi Les,
Yes, the date code interpretation is correct at week 42 of 1992.
The letter "E" represents the manufacturer's pattern code (part of the US Department of Transport identification code necessary for product recalls) and can be one or two or three characters as decreed by the US DOT Regulations, (FMVSS 574.5 - Tire Identification Requirements). In this case E was assigned to the Avon AM22 (bias belted) tyre range and was also used for the Avon ST22 radial range (same tread pattern).
I cannot be precise over dates of manufacture without searching the archives, but from memory AM22 and ST22 ran during the 1980's and early 1990's before being superseded by later designs.
This tyre is too old to be offered for sale and we would definitely not recommend this tyre is used. The British Rubber Manufacturers Association advise tyres should be used within 6 years of manufacture. The tyre should then be removed after a total of 10 years.
Avon recommend tyres should be used within 5 years of manufacture. The tyre should then be removed after a total of 7 years.
I hope this helps
Regards
Ash Vowles
Motorcycle Design Engineer
AVowles@coopertire.com
www.avon-tyres.co.uk/motorcycle
/ends
Hope this clears this up for you completely.....