building a riser for LB limbs

[khardrunner]

So after talking to Dave from Hitman longbows, I've figured out that the riser originally built for my windwalker kit bow was cut at too steep of an angle for the limbs. Instead of the standard 9 degrees or so for a longbow, the riser is about 21 deg on both sides. The guy who sold it to me messed it up with his rough cut and I just finished it not knowing that I should have checked his cut first.

here's a link to the thread when I thought I would need limbs built...
http://tradgang.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=1;t=112016

So, I'm considering building a proper riser for the limbs. Nothing fancy, just a functional riser. I'd like to get something that may work with the limbs I have.

So...
1) do I need to make a laminated riser or can I somehow do a 1 piece from a block of wood?
2) can I just try to pattern it off of the old riser but simply change the angle or should I try to get bingham plans
3) Where should I start/what other questions do I need to ask/answer?