How lovely, Carolyn. I remember my grannie having vases similar to these.
For cleaning I would suggest you try first with a silver polishing cloth. Don't use a cleaner intended for brass as it is much harsher than silver cleaners. If that doesn't do the trick then look for a silver cleaning liquid and try it on the base first where it won't be obvious if it causes a problem. Silver polishers work really well on brass, my son used to use it on his brass belt buckle years ago.
Can't help you with the handle problem though, sorry.