Can dad get re-assessed for his VA 10% disability from WWII?

His feet are terrible from trenchfoot plus other problems from his injuries have worsened. Also, he says his dreams are bad again at night and he hates to go to sleep and I'm sure there was no documentation of that at the time.

He's only used his private insurance all these years, never has used any VA services, but his medicines are quite expensive now and I'd at least like to get some help with his Rx costs.