John,
No problem at all. I'm very interested in your experience as we are following a very similar path.

Did you install the Jelco yourself? Did you use an arm plate from Dave (Sound HiFi)? I am wondering what kind of VTA I will have with the Jelco and if I'll need a spacer with my 103 on the AT LH-18.

How much mass did the lead spacer add? I'm also curious about the counterweight. I just noticed that Dave sells a heavier counterweight for the 750. I wonder if that's needed when using a 103 with a headshell mass 18g or over.

Last thing - (this may be a really dumb question, but I've never mounted a new tonearm before) - the bottom of the tonearm is like a spindle that sits in the base and the base gets screwed into the arm plate. What keeps the spindle aligned in the correct position and prevents it from turning?
Jason