Here are some pics of a nice Porpoise Universal I have just picked up. All the rubber bits are in good shape, had a quick peak at the diaphragm and it is nice and soft. unfortunately it seems that the LP hose has been replaced by gluing a new hose into the original end fittings!!
This one is obviously one of the later models as it has a purge button and the Australian Divers Spiro label so it is after L'Air Liquide bought out Teds business. I am hoping YankDownUnder might be able to give some more info on this particular model as the others I have seen have (on the net and actually) been pre Spiro.