looks like you have an interference seized up fit. OD shaft to ID washer. if it was mine, i would put some BP on it. at seizure point. applied with end of used toothpick into bristles. and the BP into a container. i have a BP jar/w lid. i rarely spray thru tube. usually brush apply out of jar. and then no mess! and jar prevents rapid evaps. a few drops spread around. full circle. couple times. let it sit an hr or so. or even overnite. then i would apply a drop or two 30 wt engine oil full circle. then i would lightly tap the 4 points of compass. ideally, small drift, small ball peen. trying to get it to wedge up and off the interference fitment. seat. if that was slow going, i would try to get something, even a box cutter blade edge in under washer. issue at point, is to wedge the washer up and off
the seat!
good luck, let us know how it turned out. i like 044 posts, got one i am working on, too.
i have run into this situation from time to time and this approach has worked for me.