Actually, if it was stored in a shop and didn't draw tons of moisture and dry rot all the rubber bits, here's what I'd do... I'd put the regulators on the tanks, put the hoses on the regulators, put the torch on the hoses. Keep the torch turned off. Turn pressure on the tanks, turn the regulators up to pressurize the hoses, turn the tanks off, then let it set for 24 hours. With the small amount of gasses stored in the hose, there's not much danger of some major explosion if it leaks off. If there is still pressure stored in the lines after setting for 24 hours, the torch, hoses, and regulators are perfectly leak free and I'd not have any issue using them 10 hours a day.
Gas and oxygen doesn't go bad. As long as the tanks are mostly rust free, they can be recertified even if a new valve needs installed. Wait until they are empty to do this.
I have a 50' hose set that is about 35 years old and still flawless. When not in use, I have a small 4'x2'x2' plastic truck toolbox the hoses, gauges/regulators, and torch all go into. In the bottom of that box is about 5 dozen or so large silica gel desiccant packs.
Also, any time other than when doing the test for leaks, you should always back the regulators off as leaving them screwed in will mess with the diaphragm inside and cause them to read improperly and fail prematurely.
