And, to beat an old horse, here's an article from March of 1955, promoting the engine balancing service at Tim's Precision Engines. Note the ad for "Blair's Auto Parts" on the lower left (Midas, anyone?), and the article about the upcoming 6th running of the Pebble Beach road race at the top left. A short mention of the little car show they were throwing out on the lawn there, too!
They may have called it a Merrill balancer but it was made by Stewart Warner....
We bought one in January of 1955 and immediatly started modifying it.
As they came, the bed was not long enough to handle big diesel truck and tractor cranks..A simple fabricated extension fixed that.
We balanced most of the blower impellers for the unlimited hydro's and
the amplifier was not sensitive enough for that job so we added a preamplifier that increased the sensitivity by 10 times. That was done with vacuum tubes in those days. Frankenstien technology by today's standards.