I took a better picture of the panel for this yesterday
http://bitsavers.org/pdf/dlcCompany/cowculator
Other than a couple of want-ads from the early 60's I've
not been able to turn up any more information on this.
I'm assuming you optimize by adjusting the parameters to
zero on the meter.
Other than what is on the panel, I've not found anything
on the DLC Company in Linthicum, Md.