Chris:
The explanation of signexp is as follows:

signexp is the sign and exponent portion of the floating-point number, extracted from the rightmost two bytes (four hexadecimal characters) of crbx and reordered so the bits read left-to-right in decreasing significance.

I think there is a minor error in the statement. Shouldn't it be "so the BYTES read left-to-right ..."? After all, the trailing 14C0 in crbx is being put in signexp as C014, i.e. within each byte, bit order is preserved (i.e. C0 is C0 and 14 is 14). If it were reverse ordered at the bit level, I believe it would be 0328.