Can you spot a C64 mouse

[pyrre]

Hi

A little challenge for you which in truth if you know an easy way I would love to know. I sift through various Amiga mice in the hope of discovering the Holy Grail of mice.. the 1351 for the C64. I have yet to discover one distinguishable aspect that sets them apart other than trying them. See if you can tell the difference.

http://www.scuzzscink.com/amiga/scuzzblog_december17/scuzzblogddecember17_0804.htm

I wonder if there will be an optical replacement for that mouse