Scope fogging/repair question

I have an old Redfield that I have on a "backup" gun that I used this year. I'm sure I've read the new Redfield company does not services the older scopes. I used the backup this year and had it fog up when I had my only chance at some cow elk after a cold and wet snow. So, anyone know if I could just take it apart and add new nitrogen and reseal it? Not sure where I'd get any nitro but just thought I'd see if anyone has any experience. I hate to throw it away and thought it would obviously be easier to buy a new "low priced" scope ($200 range) but didn't know how involved it is to fix it. Probably more trouble than it's worth but thought I'd ask if anyone has tried any DIY repairs.

Yeah, take it apart, get some nitrogen from Harbor Freight and charge it back up and you'll be good to go.

I would call Leupold. Since they are making Redfield scopes now. Either they will say yes or no

I wouldn't have guessed I could get nitro at HF so I'll check it out and see what I can find online. I'm hoping the seals do not need to be replaced as that might be difficult but we'll find out. Thanks for the HF tip as there's one not far from me.