A few questions for the Replica Builders

[Knightfan82]

Hi

I've been trying to put together a KITT voice box for a number of years. I know I can buy the unit but I want to try to built a cheeper alternative. So far I've had very little sucess. Mostly because of two reasons:

1) Most of the diagrams I have found Requires an IC LM3515, which has been very hard to find.

2) Most alternative diagrams are done in a way that I can't figure out (see Ex below).

Do any of you know of an alternative I can use? Also how big is the voice Box (Length, etc)?