Fuel tanker question

I drive for a small fuel company in the Midwest and have ended up with trailer #1. Shop tells me it is in fact their very first semi trailer the company bought, and was made in the 70’s.

A decade or so ago they slapped an air suspension on it, which goes down the road better (my first trailer there last year was not air ride; I hadn’t pulled a trailer riding on springs since I started driving in 2002) but all the drains are at the rear of the compartments and there’s no dump valve, so it sometimes doesn’t empty out very well. Otherwise it’s functional. I can see why they aren’t discarded, looking at trailer listings, a guy could buy a pretty nice tractor for the price of a newer fuel trailer.

I’d be a lot happier if the trailer was as nice and new as the truck pulling it, though. Or even if it was half as old. It’s a bit sorry looking and lacking in modernity.