I haven't used these or actual seen a pair live, but they look very similar to MXL's 603 or 991 series, which is a good thing. All these mics are made in China using the classic Schoeps TL topology, albeit, with lower grade resistor, caps, diodes, etc. They are easily modified and all cheap components can be replaced with higher grade ones.
I basically rebuilt 2 991's and 990's. The 990 is a side address sdc, or a 991 in a differant body. I replaced 12 components in each mic, removed redundant screens and modified the cap, which in your case it looks as though M-audio did not go down the road MXL did with the body, therefore the diaphram is fairly close to the end of the cap. Not so, with the MXL, which I machined down.
Take them apart and see what type of components were used. Modifying your mic might make a good mic a truly great mic.
BTW, I bet the MXL omni caps would fit them and can be had on e-bay for $38 a pair. I would suggest that you machine the lip down as to improve the sound on them, though.
Ray