The 408338 MPE-850 Fuel filter / Fuel Pressure Regulator is used for many Textron MPE-850 applications. It is also the same as the Williams 07-0370 MPE-850 fuel filter.

103450 MPE-750 fuel filter is different from the MPE-850 version, and is available here; https://weberpower.com/parts-weber-high-pressure-fuel-filter.html

The 103397 suction side pre-filter is here; https://weberpower.com/parts-weber-fuel-filter.html