The Coldwell Lawn Mower Co. of Newburg, NY was one of Fuller & Johnson's better customers.  From 1924 to 1926 Coldwell purchased 1020 model N, NB and NC engines from 1 1/2 to 3 1/2hp to power their mowers.  To power Coldwell's model L mower F&J shipped 3301 of their little 3 1/2hp radiator cooled engines from 1923 to 1927.  These were previously used on F&J's own in house built mower.  The two were very similar, the major difference being that the F&J mower had its engine mounted 180° from the way Coldwell had theirs on the model L.  Here is where things get tricky.  In 1927 Coldwell announced it would go into the engine business, having previously purchased engines from F&J and other manufacturers.  During a director's meeting in January of that year F&J stated it could build it's own mowers for $100-$105 and retail them for $225.  It was suggested that F&J could possibly partner up with another firm to handle their mowers.  It was also stated that before Coldwell's announcement they had built 1200 mowers.  I've not been able to determine if that was the approximate number of mowers F&J had built themselves in the late teens or if the quoted figure referred to some other manufacturing arrangement with Coldwell. 

The Coldwell model L with F&J's special mower engine

For large estates this gang mower attachment helped get the job done quickly