School me on SCBA Tank Filling with a Nitrogen Tank

[Norcal]

I have 30min & 60min Drager SCBA Tanks that are past their 15-year life certification so no longer can get them filled at Dive/Paintball shops. Have a line on a full tank of Nitrogen that is described as Size A - 51" x 9" for $200, possibly $150 if I offer less. I'm unsure based what PSI the tank is rated at - can anyone tell by looking at these photos? I have a friend who's a Welder/Fabricator that knows another guy that supposedly can refill it for FREE!

Also, what valving or adapters would I need to source in order to fill my SCBA's? I only have a Joe Brancato fill adapter with gauge, bleeder, If the Nitrogen tank is 6000psi, how many fills would I be able to do on my 60min tank?

[Norcal]

[x3baddad]

Ok that is a 250 size nitrogen tank it is OUT of Test last test 2007 has been out since 2017 they are filled to 2400 psi. If this passes a hydro test it would be a great tank to use with a HPA compressor to fill your 300 bar bottles all you need is a regulator to drop the delivery pressure to about 10psi to feed the compressor and a hose and fitting to hook up to said compressor.

[bchannell]

Just my .02, but before I'd go messing with a with 6k psi n2, I'd get me a regular n2 tank and a GX compressor and feed the n2 to the compressor. I'm thinking it:
1) would be cheaper than buying regulators for 6k pse
2) be no heavy bottles to deal with
3) a small 40 cu/ft n2 bottle will last a good month or more of heavy shooting, and cost $15 to refill.
4) you'd have the compressor in case you wanted to go back to air
The tank you're looking at is a 2265psi, and if you get it hydro'd and use a compressor, that would last a long time shooting heavily. That's a good buy if hydro isn't an arm and a leg. Around here hydros are $50 give or take, I haven't had one checked for a few years. Last one was 30 some odd dollars.

[Norcal]

So, if I bought a GX CS4 Compressor and used this 2245psi Nitrogen Tank to fill my 60min SCBA, any idea how many fills I would get?

[Norcal]

Would likely be filling my tank from around 3k to 4500.