$40 mistake? 2216 psi tank

So I found a Craigslist listing for an unused SCBA tank and breathing mask. The guy said it was unused as he bought it for a job 15-20 years ago that never happened and he put in away. He was asking $200 but I told him nobody would fill it as it was over 15 years. I offered him $40 and he said yes. I figured I'd fill it either with a future-owned compressor or through my brother-in-law (volunteer fire fighter).

Picked up the tank yesterday and didn't realize until I got home, it's a 2216 psi tank! My PCP is a Marauder so not much I can do with that. So question is what do I do with it? Buy a Discovery and tune it to low pressure fill? Just use it to fill my tires? Ideas?
 
I have 2 SCBA tanks that are 3000psi and they're just sitting in my attic because I have a 72cuft. TigerShark tank I bought in February from Joe Brancato but I plan on buying a cascade valve and using those two tanks together for around the house and tuning and then I'll just use my TigerShark tank for out on hunting trips.
 
I would count it as a $40 mistake and see if you can sell it. 2216 psi isn't much to work with even for a discovery. You might not even get the discovery to 2000 psi. My tank usually has to be at least 30 bar (400 psi) above the pressure I want to end up with in my gun. So for my vulcan that takes 250 bar (3625 psi) I need my tank to be close to 280 bar (4000 psi)