Congratulations to Mr and Mrs Fifer. What a wonderful landmark to reach. My paternal gran and granpa reached 50, my mum and dad just shy of the 50 reaching 49. My wife and I are due to reach 40 in a matter of days, but 60 takes some going. You must have been drinking from the fountain of youth, well done.
Feeding fresh veg, if they are not cleaned properly, could introduce a risk. I think they should be rinsed thoroughly, steeped in salt water, then rinsed again, but someone will know the correct prep and post it for sure.
You can give greens in pellet form by feeding rabbit pellets. Make sure they have a high alfalfa content. Used to be able to get them chicken pellet size, but Harrisons do some slightly larger, but still digestible. No risk of worms, etc via pellets.