Black rubberised corners

hi, I picked up my Landy today and have spent the afternoon giving it a good cut and polish. The car has been parked undermine trees so the paintwork was a mess of sap and needles. While I was cleaning the bonnet I noticed a triangular rubberised bit at each corner of the windscreen. I'm not sure what their purpose is but they look pretty perished. Where can I get some new ones? Also, what is the best workshop manual to get?
Thanks in advance

Have you got a picture? I can't quite visualise what you mean.