D 19 used as print dev

…I have found 3 x5 litre bags of it. Is it worth trying or stick to normal print dev?

D-19 is a high-contrast film developer, not really useful for ordinary continuous-tone photography. As I recall, one use for it was as the first developer in Kodak's old b/w direct-reversal process.
So it might work as a paper developer, which are more contrasty than regular film developers. Worth a try, all you are risking is a few hours of darkroom time and a few sheets os paper.
Pro tip- have a tray of your regular paper developer ready and print the same negatives, processing through each developer. That way you'll know directly not only "if it works", but more importantly, "how it compares". And let us know your results, please!

I've always used it to get more contrast out of HP5, never for print developing. Give 'er a go, and report back!

Maybe look at the formula, compare it with a standard paper developer, then amend the proportions of some ingredients. It might not need much adjustment. It would be nice to not waste it, and presumably you don't want to use it on film.