Is there a cheekpad that won't interfere with the telescoping of the stock?  I know nothing about cheekpads for ARs so maybe none of them interfere.

I mounted my TriPower on the carry handle and I can sight through it comfortably, but when I test by closing my eyes, putting my cheek tenderly against the stock in a comfortable position, and open my eyes my head could be about 1/2" higher or the sight about 1/2" lower.  If there is no solution I'll survive, but if something can alleviate this 1/2" difference that would be perfect.

Nothing?  

Hey Bucko, there ARE some cheek rests available for collapsing stocks.  Try looking at www.bushmaster.com or www.dpmsinc.com they should only cost 20-30 bucks.