I have been able to make some progress in my reestablishment of the rear window seals on my 142. I sourced a poor pair of seals,(they had been discarded). the seals are of an "interesting" construction. They are made of two pieces, the outer part being a rubber strip of a complicated profile, they separate from each other quite easily. The sun strikes the horizontal part of the seal and after 40 years it has deteriorated badly, the upper section however being under the turret "Lip"
however has survived rather better, and as this is a long curved piece, it is able to be cut to the lower length and should fare quite well.

Thank you for your input, I shall be trying to find some 242 seals as well