I had the same problem awhile ago as I was looking for some blue and black G10 in 1" and came up with nothing.
After talking to Chuck at Alpha, I did laminate four 1/4" pieces together and it worked out beautifully. I used the Duraflex epoxy from Alpha as well, but Devcon would probably work ok as well. As an added benefit, I was able to cut the hole for the tang (through tang in this case) prior to assembly so it was MUCH easier than trying to do it in a block.
I have done it a few more times since then and have no problems. As a matter of fact, I had one handle that I glued up, put the knife together, realized the tang/handle joint was slightly out of square and thought I'd try to take it off with a 3lb sledge....
The handle is still on and in perfect shape
Pay attention when assembling the layers though, and assemble the pieces face to back or you will get wide layers where they are joined-although that could be used to effect too.