I checked with Solidworks to evaluate dimensions in dwg files and 19.26mm is the correct spacing (with the real board i have approximately the same dimension.
for the top side i have 1.27mm (1/2 inch) and with the left side the cote is 1.30mm
for the top side i have 1.27mm (1/2 inch) and with the left side the cote is 1.30mm