Matters to me since I appreciate the effort and precise work Michel expended to produce those accurate masks. I assume his leaving off the scale was a slight oversight.
Hannover - the masks scale out to exactly 1/48 according to my reference. Thus it would be easy to go, for example, to 1/72 (66.6%) or 1/32 (150%) using the Transform/Scale feature in Studio (upper right panel in illustration below) :
There are many Google references for mask placement, including this excellent VF-161 web site.
Gene K