P3D more double depth

[CanterMike@xxxxxxx]

Well, now that I've gotten several answers & tips (that, as usual, don't
always agree! [insert your choice of emoticon here]) I still have some
questions on "double depth".

Does anyone want to tackle how this differs from simply using a mask with a
different aperture (like using a 4P mask instead of a standard 5P, or using a
5P mask instead of a 7P)?  

Is the "cut & shut" method (removing a strip from the middle of the mask)
actually better than masking the apertures, or only easier?

Can a "cut & shut" be done with RBT or cardboard mounts (actual experience
counts more than theory here)?

I await the respnse(s).

Thanks, 
M


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