Sorry to put a dampener on it but
That does look a lot like a bcd inflator hose (if its on the low pressure port of the 1st stage you will not be able to get more than a few hundred psi out of it
That type of hose is only rated for low pressure, if its on a high pressure port you may well end up picking bits of hose out of your eyes should you try to fill from it
Ok from a diving point of view
From the photos Its obviously a A clamp 200bar cylinder + diving 1st + 2nd stage so even the cylinder has very limited value even with the correct fill kit
How much do you know about its history what is the test date on the cylinder how old are the 1st + 2nd stage and do you have a service history, dive kit needs to have an yearly service + rebuild parts that costs about £70 for most Reg sets and £30 for a strip down and clean for the cylinder (that’s why there is so much untested old cheap diving kit for sale on Ebay) and why there are so many diving accidents, would you trust your life to someone else’s reject life support system below 30 meters? You be amazed the number of people that do
I almost feel like taking it off your hands so I can get it serviced and sell it on to prevent some numpty (newly qualified diver) from killing them self’s when it fails in an out of air emergency
How much does this set owe you ?
At the very least if you sell this kit make sure who ever gets there hands on it is a qualified diver and gets a service done on it
This is the cheapest online REG servicing company I have found that will do the reg for £35 + parts
http://cgi.ebay.co.uk/Low-Cost-Scuba-Diving-Regulator-Servicing-35_W0QQitemZ220075769736QQihZ012QQcategoryZ16056QQrdZ1QQcmdZViewItem
Btw I’m a rescue diver + mixed gas deep diver so I know a bit out this sort of kit