Any of you Philly/So Jersey guys know this place? ... here is some info from the 'store' owners write up:
8th Street Music Center was founded in Philadelphia, Pennsylvania in 1940. Originally, the store was located at 8th and Market Streets (hence our name) until we moved to our previous location at 1023 Arch Street in the mid 1970's.

If the ad is legit, it might be a good sign that the PA600 is in distribution in the US ...

PS ... their ad also shows an address of:
7815 Airport Hwy Pennsauken NJ