Not sure if you had seen it yet but according to the VIN registry on here, that VIN falls in line with a grouping of some 1990 TX SSP VINs. See this link and scroll down to it:
http://www.specialservicemustang.net/VINlist/90VIN.html
LF149430 and LF149433 are documented as TX SSP’s, but LF149431 and LF149432 in that same grouping do not have info (yet).
Hope that was helpful.