old A/C type ratings
I knew a pilot who had something like 30,000+ hours (I saw his logbooks) before he died (of cancer, at 77), and he had type ratings for everything you could imagine. Over 100 when he last counted.
He complained that if he wanted to keep them all current, he would do nothing each year but take checkride after checkride, and would have no time to fly for revenue. At one time he owned a DC-7F (which was entered by an aluminum extension ladder, and secured by a padlock and hasp on the door!) which he had bought sans engines from a farmer's field for $10,000 - and once the farmer had the money, he advised that the rent was $2,000 a month and kindly getcher blankety blank aeroplane outta my dang field . . . took him eight months, but he did it. He offered me a tour of the airplane, but it wasn't airworthy, so he never did offer me a ride (which was a great relief to me.)
Big, old transport aircraft make me nervous. They have moved to the bottom of the revenue food chain because they are uneconomical to operate (fuel and maintenance hogs), and the type of marginal operators that buy them are the least able to afford the maintenance. That's a bad combination, especially if said operators are in part of the world where you can't get good maintenance even if you can afford it.
My opinion is that unless you have a solid job offer flying one of these "classic" airliners (pronounced "dinosaur"), you might want to spend your money on type ratings for new, safe, well maintained airplanes.
Best Regards,
Echo Mike