Did you consider this approach, SD? If you could get your hands on the Nitrogen, anyway.
And, after re-reading, find a business to accept delivery. 
THIS VESSEL HAS BEEN TESTED TO MAINTAIN ANTI-OXIDATION PROPERTIES INDEFINITELY WHEN PUSH-GAS USED IS MEDICAL GRADE NITROGEN
I have considered storing my nic in kegs pressurised with argon or nitrogen (you can buy 5lt kegs and do it yourself)
I bet a new 20 or 30 lb. propane(gas grill) bottle could be revamped, as well. Or, even the same size vessel that is made to transport compressed air. Would have to adapt fittings for pressurizing, but dispensing with a 1/4 turn ball valve and hose should work
Cleanliness and such, of the tank are issues though, too.
Actually, the longer I think about it, stainless is probably the ‘cleanest’ option for storing something I’m gonna be inhaling 
Don’t think I haven’t thought about push gassing.
THIS VESSEL HAS BEEN TESTED TO MAINTAIN ANTI-OXIDATION PROPERTIES INDEFINITELY WHEN PUSH-GAS USED IS MEDICAL GRADE NITROGEN, 1 YEAR WHEN PUSH-GAS IS 50/50 NITROGEN CO2 MIX-GAS ( AKA BEER-GAS) AND 8 MONTHS USING FOOD GRADE CO2.
Gas type matters…
