Information on these two please!

Maybe a vin would give a clew about year? Maybe too long ago to conform? Anyway, I've seen vin be questionable: my MTS has a vin with year later date code than what I was told it was??

Clue...don't want to promote bad spelling!

The first bike looks like an early 500 Pantah, from '79 - '81. It has the smaller front calipers compared to a 600. It has been heavily modified, so could have parts from other models.

The older bike looks like a 250 from the early - mid '60s. (I don't have much expertise on this era of Ducati). Ian Falloon has documented the history of Ducati's models, and would be a good resource to pinpoint the exact model.