Fill a 3D gap under letters

Hey guys,

I'm having an issue right now filling in a gap between some raised letters and the face of the part. The letters needed be perpendicular to the bottom of the piece so the part can be removed from a mold vertically without the letters catching on the mold. I need to fill in the gap beneath the letters with a triangle and make it perpendicular to the part face the letters sit on. Hopefully the attached picture better show what I am talking about. I have tried doing lofts and boundary fills but have been met with zero thickness errors.

Any help would be appreciated.

Thank you,

Matt

SolidworksParts And Features