[pianotech] R. Rathke & Sons info?

[Phil @ EMV Keys]

Can someone provide any info at all on "R. Rathke & Sons" pianos. Pierce 
doesn't have anything other than "St. Petersburg, Russia, 1868" Any info 
at all is appreciated. It's a 6'+ grand which my client purchased and 
had shipped over when she came to Canada.

Thanks, Phil