[Speedslug]

I guess you are going to have to throw the dice and give them a thorough going over looking for anything that gives you concern.

Since I use only house hold natural gas which runs at a pressure of something like one quarter of a pound per square inch and a 10 lpm oxycon I consider my 12 year old hoses still safe.

Mine have been coiled under my bench, in the house, in the dark and un-moved and lightly used at that.

If I had them out in the cold / hot garage up here in Minnesota all that time and / or dragged in and out of there into the sun and on the concrete or gravel driveway 10 times a summer and had them running at 5psi fuel and 15 psi oxygen I would replace them at 10 years old even if they looked fine.

Rubber has a shelf life and even the rubber inside pressure regulators should be replaced or over hauled at ten years even if they just sit in a drawer all that time.
Fuel and oxygen bottles tend to run at 1000 psi or better and you just cant afford age related failures at those kinds of pressures.

Hope this helps.