Welcome to the forum.
Not hypalon. These leisure SIBs were strongan duotex (Zodiac's own PVC fabric), thermo-bonded and glued. Boat is 1998 going by your transom plate. For hypalon - you need to be looking for grey Zodiac GRs (Grand Raids). Come with inter-communicating valves, D rings at the bow and aluminium floor boards with an inflatable keel. Defender sell something very similar now - the MilPro FC470.
Get that transom top edge sealed or you'll get water ingress and then tatties over the side as we say here in Scotland!