My Cricket ha a black hose on the propane side and a green hose on the oxy side - that WAS attached to the secondhand oxy-con unit.
It looks like the oxy-con needs a service trip, as the poor thing beeps at regular intervals and the red light tagged High is flashing on the circuit board - so I thought I would try with bottled oxy for a couple of weeks until the non-rent paycheque...
Dad was a welder, so not worried about managing larger tanks, just not sure about the logistics of the connection. We do have a few welding supply places here, so getting the right pieces should be fairly easy.
Off to read the entire Safety section now