Dear David,
As I said before, you can’t directly get M, C, K, and F because FAST v8 linearization does not output M, but you can get I, [ M^-1 ]*C, [ M^-1 ]*K, and [ M^-1 ]*F. The latter, [ M^-1 ]*F, is available in the B matrix instead of the A matrix. This first-order form should also be amendable for controls design.
Best regards,