I ummed and arrd for a long time about renewing my Firestone tyres which were about the same age. Plenty of tread, but who knows what happened to them over the seventeen years prior to my ownership.
I did quite a lot of research and one of the things I read was that plasticisers are released when are when a tyre moves and they help it to retain its integrity. I certainly didn’t find anyone who thought for one moment that 18-year-old tires should be on a car for normal driving.
I bit the bullet and bought a set of four Dunlops with new Michelin tubes (don’t even consider buying any other make) and another worry was off the list! Whether Cromadoras need tubes I don’t know, but a specialist tyre fitting garage should be able tell immediately. You could always send them a photo as I did. My rims are FPS which were a factory option in 1975 and tubes were needed. The tyres would have sealed perfectly, but in the event of a puncture the tyre would almost certainly come off the rim.