We both have about the same amount of experience, but I've always had access to an oscilloscope (I built one for my school in 1962). I've built many programmers, since 1976 or so - but never without a 'scope. I don't build them any more since I have easy access to ISP.

I suspect that many of the professionals on this board have similar experience to mine: I've never needed to build anything without a 'scope, and therefore have no experience in assisting someone in your position.