If you are looking for a two-hose regulator to actually dive with, a US Divers or Voit is the only way to go. The design has been around since the 1940's and was improved upon until 1975 when production ceased. They used a minimum of parts, with a proven design that would last a lifetime. Also, more US Divers and Voit regulators were made than any other two hose regulator, so more new-old-stock and used parts are available. I specialize in US Divers and Voit two hose regulators, but I can service some other brands as well.
1954 U.S. Divers (Trademark) Two Stage, Double Hose Regulator, Serial Number 26543. This is an all original, un-molested survivor with the original one-piece hose assembly and Tinnerman hose clamps. It has not been tested. Price $675.00.
EARLY 1960's U.S. DIVERS CALYPSO SINGLE HOSE REGULATOR
This is the second model of single hose regulator that U.S. Divers ever sold, after the AquaMatic. It has one LP and one HP port, and the HP port has the hard-to-find pin type pressure indicator that tells you how much pressure is in the tank. This regulator has shiny chrome and all the labels. The exhaust tee is starting to perish but is still fully functional. The regulator does work but because of its 60 plus years of age is being sold "as is". Price $65.00.
US Divers DW Mistrals, DA Aqua-Masters and DA Navy Approved Two Hose Regulators.
I always have these models in stock, complete with hose assemblies, rebuilt and ready to dive. Priced from $350 and up, depending on condition and rarity. Please inquire.