Hello, Peter,
I would suggest that you carefully sand or grind the face of each side of the original
blade clamps. They are probably just worn from use and if you file them down to
close to a smooth surface, they will then hold the blades well again.
Another possibility is to allow a tool and die maker type acquaintance take measurements
and make you a couple sets of clamps. If you don't have any personal friends that happen to
work that type of occupation, perhaps there is a machine shop close by where you could inquire about prices for such a small piece or, better yet, a trade school where a student could do it for you with the permission from his instructor.
Here is a link to Grizzly with an address that you could write and inquire about the price but,
I left this as my last suggestion because the price would probably be too excessive unless you
could convince them to just put the clamps in a bubble pouch envelope and mail it to you without
a huge price increase for postage and handling.
http://cdn0.grizzly.com/manuals/g1060_m.pdfGood luck and God Bless!
Spirithorse