Well glued the 2 sides to the cardboard steps last night but found even with very little pressure on the clamps it was bending the cardboard, So decided to turn whole thing onto its side and just put a weight onto the top. Everything OK so left it for a good nights sleep (thats me not the steps).
Today I find that during the night one of the sides has moved down and is lower than the other side @;**7 and other nautical language.
It also transpires that I have done such a good job with the glue it will not budge.
Can I live with it at different heights NO. So its chop it up and try again OR add some acrylic to each of the low sides to bring them into equal sizes, we shall see how it goes !!!!