Ok there is a way to do this its non conventional and i'll probably get some flack. ditch the breather and peel ply and anything else you might have in there, just vacuum down to your smooth table get some cheap super six poly this is you top part of your bag do your epoxy/fiber board layup as before make sure you have breather around the perimeter but not on the finish board surface turn on your vacuum with no wrinkles on the board surface. You will see air trapped between the plastic and the laminate surface you need to squeegee this out to the rails you will remove resin with the air and end up with a reasonable smooth surface, this squeegee part is alot of work it takes 15-20 mins. At this stage you will see how much extra resin is in your laminate as your fiber will be floating in it if you press your finger into the plastic and end up seeing the dimple your not done squeegeeing. Your top surface will still be slightly wavy and you will see any shapeing mistakes, but There is a few other tricks as well too make a totally flat smooth top surface. After you are done sqeegeeing You can create a second vacuum bag on top of your existing still uncured lammed surface place a 3mm plastic sheet material that will conform to your board shape and some breather on it if you like and vacuum this down on top of your board it will smooth out and bridge any slight uneveness If you want to create a chanell in the bottom you will need another layer of 3-4mm waxed for release plastic sheet material use this as a casset to do your layup on then place whatever you want to create the channel under your board on the rocker table surface, and vacuum it down in the first bagging.

good luck
Cheers
Jim

Simpes, Just use the pre-cured top sheet method comes out of the bag finished and only needing the flashing cut off.

Search for my Porker posting, I use this method for my boards in days gone by.