Greenhouse Glazing Seal - Identification?

Hi again!

Further to my previous post about glazing clips for an old Robinsons Royale - we found that some of the stainless Z clips work fine. Now we have a problem with the glazing seal... The seal has deteriorated so we are looking for more of the same. By a stroke of luck we did have some of the exact same seal which had been in a cupboard for years - but nowhere near enough. I contacted Robinsons again - who were I'm afraid to say of no help at all. I've enclosed a couple of images of the seal. It is light grey in colour and more of a flexible PVC as opposed to rubber. Anyone have any ideas were we might be able to find some of this? Thanks again!

 

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwiF15TgzKjQAhVBOMAKHdl8CVAQFggkMAA&url=http%3A%2F%2Fwww.sealsdirect.co.uk%2F&usg=AFQjCNEKxfn75khBPqJtrljmF2trlcs92w

http://www.sealsdirect.co.uk/pdf/TFS3302DR.pdf

Found this hope it helps

This one has Robinsons but is different to yours scrool to bottom of page

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=4&cad=rja&uact=8&ved=0ahUKEwjp4Mz5yqjQAhWJCsAKHXLsBaAQFgiqATAD&url=https://www.greenhousepeople.co.uk/categories/spare-parts/glazing/&usg=AFQjCNGiT5riX-fTvwZcm5hnwL1yQoy5hQ