Odd British Slogan

I was at a stamp show today and came across these British covers with slogan cancels. Normally, they would be pretty well straight forward, but, there is this one pair I found. The slogan commemorates the same event on each cover but one has Windsor / Berks as the location of origin. The other cover with the same slogan has a triangle with #890 in it. Is this common? How does one determine where the cancel originated from?

Chimo

Bujutsu

I'm not sure if this list still applies as late as 1961, but if it does 890 = Windsor (Berkshire) which fits the first scanned postmark, too. Not sure why the different markings, but maybe some UK specialist can enlighten us.

http://gbstamp.co.uk/article/index-...ons-143.html

(In any case, it seems as though this is a good list to keep handy.)

Thanks for that list wt1.

This will be a keeper with me and will come in handy.

Chimo

Bujutsu