Matthew Ridout 1980 "Nola Rae: Some great fools from history"

I have recently acquired a 1980 original poster, details below.

1980 Matthew Ridout - creator
"Nola Rae: Some great fools from history"
Dimensions: 29x33inches

I have done a little research on the product and have found that Nola Rae along with Matthew Ridout founded the London Mime Theatre in 1974 and are still working together today. Nola is an international mime artist with Matthew the design and technical manager designing and constructing all sets, props, costumes and posters for their productions.

I'm pretty clueless when it comes to vintage posters so any expert advice and possible valuations would be much appreciated.

I've emailed several vintage poster places but no where is particularly being that helpful so i thought i would try here.

I'm pretty sure it's original as it's mounted on a board which has a 80's newspaper article attached to the other side. I know this necessarily doesn't mean it is original but i've looked at the other criteria and it's pretty positive.

Any help at all would be greatly appreciated.

Leanne