Rust on a Hollyhock

I have a couple of inherited Hollyhocks (here when I moved in) both of which are distinctly sorry for themselves. The foliage on one has rust spots, and the foliage is generally sparse and poor - in its defence, it did flower this year but not as well as it did last year.

I have another that was a tiny wee thing, which I had to move to let the fences be done - I took the opportunity to relocate it somewhat, and it had grown a bit larger but did not make any attempt at flowering.

Now, I bought a packet of hollyhock seeds for next year, so I will hopefully have some replacements to play with - however, I am not sure whether I should try and save the existing two or just dig them up and sling them?