The last reg with the yellow hose protectors looks like a USD Cousteau or SEA (same reg and I am pretty sure Seaquest also sold it). It's basically a AL/USD Legend in a different skin. A couple of the LP ports are the larger 1/2 versions so you will need an adapter to use them with standard LP hose (or use the other 3/8 ports). While a heavy reg, it's also a good one based on the Conshelf design. The internal parts are common to all USD/AL diaphragm regs so parts are easy to get even if official service kits are not available.