Steinway question

[pjr]

How does one tell if a Steinway is from Hamburg? A friend of mine, now 
deceased, always claimed his "B" was a Hamburg Steinway (Off of a cruise 
ship).  His family is now having problems proving this to potential 
buyers.  I've always heard that the Hamburgs had a button lid lock in 
the side curve.  This one doesn't.  I've also heard that there is a 
different profile on the side of the keyboard.  Is this true?  Can you 
tell from the serial number (476778)?  Any other differences?  I'd 
appreciate your input.

Phil Ryan