Still surprised that it did not go for more.
I would have expected that the relationship between "New-In-Box" prices and "excellent condition" prices would be much farther apart on ancient gear like that.
There were millions of Model Ms built over the course of decades, for a commercial/industrial customer base, so it stands to reason that there would be lots of them left over. But Model Fs came as part of a complete system, so obviously they are more rare.