I have owned and ridden a lot of bikes, and still own a fair number, and my MeiVici is still one of the best bikes I have ever ridden. I have previously described the process I went through before I had one made for me. With a quick search I came up with
this,
this and
this page. If Serotta were still in business, I would happily pay to have another one made for electronic shifting.
The good news is, if you buy it and don't like it, other than the cost of building it up and tearing it down, you don't stand to lose much since the discount for used MeiVicis is pretty baked into the market.
I know the original owner of the bike that SoCalSteve bought. The owner actually worked at a shop that was a Serotta dealer, and spec'ed the bike to be super stiff (he had a 595 Ultra that he was trying to emulate). That frame didn't just have a 10.5 downtube, it was all 10.5 tubing. It was stiffer than the 595 Ultra.
Buying used bikes is a bit of a crap shoot, but you never know how a bike will ride until you try it. You may love it, you may hate it, and you may be indifferent.