To combine a couple of answers:
1. "It's ok to copy a design if you change the design by 10%."
"It's ok to copy a design if you are using a different stone not available from the designer."
Again, IANAL but in general either act would most likely be
construed as preparing a “derivative work,” which is a right owned by
the copyright owner and in general NOT allowed to either the
requester or to you. There are, of course, circumstances where a
court would say either was okay but I would live by the assumption
that the party plying those lines on you does NOT have the rights
(and probably fully understands they are requesting a theft and
hoping to get away with it).
I believe the VA fee (and most copyright fees in the USA) is $30,
not $35.
A recent change in the law (couple years ago) made the personal
copyright period life plus 70 years, not 50.
Counting just on your personal copies of 2D or 3D images will be of
little help should you need and choose to go to court, not everyone
will drop selling copies (if indeed they are) just from a polite
letter (though that is almost always a good way to start). At some
point you may need untamperable evidence (such as a dated
registration gives) or something that a judge or jury finds as
persuasive “proof” of copying/deriving. A record on your hard drive
when you know how to change the clock is clearly tamperable evidence.
James E. White
Inventor, Marketer, and Author of “Will It Sell? How to Determine If
Your Invention Is Profitably Marketable (Before Wasting Money on a
Patent)” Info Sites: www.willitsell.com www.inventorhome.com,
www.idearights.com www.taletyano.com www.booksforinventors.com