right I've checked the microfiche, bit confusing but I have found the following, S2FL cars all shared the same screen and surround whether HPE or coupé, the seal for this windscreen was altered in October 1978 to a two piece left and right (presumably a change of technique with the sealant). For S2FL2 this part continued with the same part numbers for the HPE but the Coupé changed to a single piece seal which is presumably the rubber type seal, on this series the part numbers for trims and seals do not match on HPE vs coupé and neither do the screens. The microfiche I use is the 9th edition which was issued late in or possibly after the end of Beta production so should include all variations. So it would seem that officially the HPE continued with a bonded screen which TBH is what I had always understood to be the case, I was always under the impression that due to the hatchback the HPE shell wasn't as stiff as the coupé and needed the benefit of a bonded windscreen to improve body rigidity. As far as I know the screens are interchangeable (but don't take my word for it I've never tried it!) so I suppose it is possible that over the years some HPE acquired coupé style screens with rubber seals, also possible that some acquired them at the factory by accident or due to parts shortages(?) although Lancia parts info is quite precise and any deliberate application of different parts should be recorded in the parts information. Also in the service manual update for the S2FL2 cars it illustrates and lists the new features for both HPE and coupé and it specifically mentions the 'new system for fitting windscreen glass and rubber trim' only for the coupé, under the HPE it just says 'windscreen and side windows surround and drip channel trim in black'.