oldtriguy1960,
Those 'perfs' look like the ski-slopes and ski-bumps on the Canada flower definitives of 2004 - 2010.
Here is a link to a site by the editor of the Unitrade Canada catalogue and to his link to his article in pdf format (Adobe Acrobat) about the serpentine die-cutting 'plates' or 'mats' of these stamps (which are printed by the company Lowe Martin.).
http://www.adminware.ca/LoweMartin/index.htmDo the USA stamps have a constant perf on every stamp or are they different? If they are different then the cobras or slopes in the cutting would be similar to how the Canada stamps are printed and cut and so the stamps would be able to be plated and those special slopes in the perfs that you have would be able to be determined to be from a certain position on the 'plate' or 'mat'(100 x 100 stamps or whatever they are).
However, if they are a constant thing occurring on every stamp in the coil or plate or whatever they have then it would be no good to plate them.
Link to topic about a perf gauge for recent serpentine perfs that cannot be measured by standard perf gauges that measure 10-18):
https://goscf.com/t/6794&SearchTerms=canada+flowerDoug