what's the best way to cut/join this?

[Jimbo]

The above pic is a side-on section of my CP.  The yellow bit is the top (with angled section at the front for spinner to sit) and the white bit is the front panel.  I want to attach the angled section to the top section.  My problem is that since the angled section is so small, making an angled cut with my circular saw is extremely difficult (the piece is not wide enough for my sawboard).  Basically, the top+angled section will velcro down onto the CP box. I'm thinking of gluing and screwing the top to the angled bit (as shown), but my main problem is how to cut the angled edges on the narrow angled bit.  The top is 18mm plywood, all other panels (inc. angled bit) are 12mm ply.

I have a plunge router, jigsaw, and circular saw to hand.

Any ideas what's the best way?  Thanks!

[sstorkel]

You need to make a jig to allow yourself to cut narrow pieces using your standard sawboard. The jig is basically an L-shaped piece of wood. It should be the same thickness and the wood you need to cut. The long leg of the 'L' should be about as wide as your sawboard. The short leg should be slightly less than the width of the piece being cut. The sawboard rests on the long leg of the 'L' and the short leg prevents the piece being cut from getting pushed forward by the saw blade.