Spot The Error

Some times just for fun we have a competition on site, It has been quite a while so I think it is high time we had another. Just to say thanks to those of you who voted to put GB Machins into first place on the top 50 website. Your votes are much appreciated, so please do continue to vote each time you visit the site.

BACK TO THE COMPETITION

This se-tenant pane was issued in the 10p London 1980 booklet, contents : 2 x 1p, Label and 1 x 8p, it was issued in Oct 1979. The stamps were Printed on the Jumelle press.

Not what you would consider a rare item and at first glance you would dismiss it as just another 10p booklet. But there is a difference to the norm if you look closely.

Last week I was at a stamp meeting and picked this up along with several other booklets, this one was actually sold for the bargain price of 50c.

Can you tell me what the error is. All replies (by email) subject "booklet" will go into a prize draw and the first correct answer (to be drawn next week) will win the booklet.

Don't forget if you do not enter you have no chance of winning, Good luck,