B.T.M.

Hope the abbreviation is ok...

You could also use the cotton-thread cuttng method, or one of the hobby 'razor saws' (really thin with a back edge) As to where to cut, cut 'em up/down, with thread held flat against the inside of the sand shield. Thats where the joint was.

I also have a few of the Dremel saw blades left, two of the smaller ones and one larger, but both are the thicker mandrel-mount, not the thinner ones that were firmly attached to the shaft. The razor-thin one (fixed mount) I had snagged in an cut and wrinkled, and was rendered unusable.

Check some store cases, I've found discontinued pieces in some cases. eBay is also a source... but quality varies.