I had the same lightbulb also as my '81 did not have a built-in regulator and really did not want any of the CW regulators. I got a small (3.34"W x 5.01"H x 2.44"D) NORGREN commercial regulator (R43-400-NNLA)at a local distributor. It has a 1/2" inlet/outlet and a 1/4" port for a 15 to 125 psig gauge. There is an easy locking adjustment knob, and a mounting bracket (5203-05). I extended my hose heat straping to wrap around the regulator then wrapped some pipe insulation around it. I have a "Y" with valves at the local faucet, I then hard pipe the regulator, that is set at 50-55 psig. I attach the water hose, with quick-connects at both ends. Then through water bay floor access to a 20 micon filter, then to a 5 micron filter. We have very good flow, no plugging, and no damage to the hose or coach. Go to NORGREN site
www.norgren.com/usa/search and search for R43.pdf that will give you a viewable spec sheet.
Ki