Building a motor bed

As some of you have seen in my other posts; I am installing a Volvo Penta 2010 in a 29 ft sailboat. Now I need to build an engine bed. I have removed the old one, and all I have now is a shaft coming out of the tube, and an empty inside of the boat. The area is pretty flat but ibviously mildly v-shaped. I have the figures for the engine and gearbox and I know the dimensions.
I plan to laminate an engine bed with glass fiber and epoxy. I have some ideas regarding the build, and how to get it in the right angle, but would certainly like to hear of your experiences.
Rough plan: Suspend the engine in the air by a chain in the workshop. Build a template out of wood that incorporates a 25mm hole which is determined by a 25mm tube attached to the gear box with the coupler. Carry that template to the boat and insert the proper prop shaft into that hole and the template should be positioned in the air just where the engine bed should have its flat surfaces. Then somehow starting from there laminate the engine bed. I do not want wood in the final product, obviously.
This is a rough idea, but i figure this must have been done many times by many.
I am building other parts of the boat out of epoxy and cloth and I am already deeply engaged in that, with plenty of resin and stuff on site - so epoxi it will be, and I am getting quite good at laminating by now.
Greetings
Runhammar

 

If you are using a wood core and have reasonable access to the area, it is simpler to position the engine first. Put the engine in its location and put wood blocks/wedges under it. Bolt on the shaft to get a rough alignment. Make a template and fabricate the beds. Slide them under the mounts (set at mid travel) and remove the blocks/wedges. Check the rough alignment, that the shaft does not touch the tube. If it is OK, mark the location of the beds, remove the engine and glass in the beds.