Cooper S Speedo "A" Suffix on 4417 Serial number

[V8JET]

Afternoon all, can anyone tell me what the "A" means after the serial number on the Speedo ? I.e 4417/22 A or 4417/18A ?

I've looked through Parnell but although they mention that the 4417 is the later Cooper S speedo after 64 I can't find any mention of the "A" suffix or what it means. Would it be Australian Market or something else?

Thanks in anticipation!
cheers

[Tagus]

I have one of these also. Mine is a Canadian export. I've wondered what the "A" represents also.