[A/S] Questions on 1979 propane tanks

["Christopher45103" <blickcd@xxxxxxx>]

I've only owned my '79 International for a few months now but have 
taken it out quite a few times.

From what I understand it has the old "unsafe" valves on the propane 
tanks and they will need to be replaced whenever I run out of the 
propane that came with the trailer and go for a refill.

I'm sure other people here with vintage A/S have had to do the same 
thing.  Has anyone had problems with the old tank passing inspection 
and being recertified?

I'm not sure if I have 30 lb or 40 lb tanks, and although there is 
supposed to be a tare wt rating on them, none of the numbers make any 
sense.  Does anyone know how to decode these?

I suspect I have 30 lb tanks because there is a similar vintage A/S 
parked about a mile from my house and I've noticed that the top of 
the handle ring on it's tanks is about even with the bottom of the 
front window.  Mine are a few inches shorter.

I did weigh my tanks a while back just to get a rough idea of how 
much was in there, but does anyone know the empty weight of a 30 lb 
tank?

Thanks,
Christopher