Roger Waring wrote:

> The screws are unknown in this country as far as I can determine ...

Maybe in the local Hardware stores they're unknown, but us manufact-
urers have easy access to them through various builder's hardware
suppliers like Baer Supply Company (they don't sell "retail", so
there's no point in giving the listers the address unless they're
prepared to commit to hardware purchases of several thousand dollars
per _month_!)

However, there is another company I've found out about that seems
to sell a _huge_ selection of Robertson-head screws, as well as the
more normal hex and Phillips-head variety.  They are:

  McFeeley's.
  1620 Wythe Road
  P.O. Box 11169
  Lynchburg, VA  24506-1169
  (800) 443-7937 VOICE
  (800) 847-7136 FAX
  http://www.mcfeeleys.com/

They're called "The Square Drive Authority".  Too bad they don't know
the correct name!  Having worked on Casavant organs, I've always
known them as Robertson-heads, too.  They also sell a number of tools,
including Robertson-head Screwdrivers and insert bits for power
screwdrivers.  Hope that helps!

Faithfully,

Richard Schneider, President
Schneider Pipe Organs, Inc., Organbuilders
Kenney, IL   61749-0137