Martin Allen has now recorded the coin and all is explained!
https://emc.fitzmuseum.cam.ac.uk/full-record/20240117?&0=10540980&1=10540981&2=10540982&3=10540983&4=10540984&5=10540985&6=10540986&7=10540987&8=10540988&9=10540989&10=10540990&11=10540991&12=10540992&13=10540993&14=10540994&15=10540995&16=10540996&17=10540997&18=10540998&19=10540999&20=10541000&21=10541001&22=10541002&23=10541003&24=10541004&25=10541005&26=10541006&27=10541007&28=10541008&29=10541009&30=10541010&31=10541011&32=10541012&33=10541013&34=10541014&35=10541015&36=10541016&37=10663673&38=10663674&39=10663675&40=10663676&41=19870154&42=19880184&43=19930227&44=19940222&45=19950173&46=19950174&47=19970154&48=20000052&49=20010662&50=20060124&51=20070062&52=20100263&53=20120085&54=20130102&55=20130350&56=20150295&57=20170052&58=20180144&59=20180289&60=20200413&61=20210408&62=20220008&63=20230112&64=20240117
Jerry