Tight Stem of Gourd Calabash

bought an old gourd calabash in summer - have smoked it many times since then & the stem always easy to remove & reconnect to clean with pipe cleaner.

intended to clean the stem again before smoking it but it was extremely !! tight - as careful as possible twisted until it finally disconnected. - will not reconnect - also the silver ring around the shank is now loose coming off easily - it was securely connected previously.

seems as if the inner connecting surface of the shank has shrunk in diameter. the stem only connects minimally - smoked it holding the body of the gourd to prevent the pipe from disconnecting.
any way to expand the shank entrance other than sand paper in case later the summer humidity may affect it & expand it naturally ?? if it is a humidity issue as now winter the air is much drier from the cold & heated apartment may have dried the entrance causing it to shrink & causing the ring to come off.
dare i dip the end of the shank into warm water to expend it, trying to connect the stem in an attempt to expand the entrance to the shank ???
calabash smokers - help - this gourd is a good smoking pipe
has this happened to any gourd calabash smokers ?
thanks