What is my XYZ worth? How much is THIS worth? Value my...

That is absolutely correct, but what the guys quoted me is irrelevant for an international market and I'll tell you why...

1) they've only sold parts internationally, and usually received a significant amount more by selling to an international audience than they would have by simply selling to people in Switzerland (with a Population of only 8 million people and significantly fewer bike enthusiasts and collectors ;) )

2) that being said, they said it's hard to get a proper appraisal as it is, as the bike is custom and they've never even seen an early Merckx Professional with Aero frame before... perhaps somebody else on the planet has, though? That's my reason for asking. I haven't been able to find one picture of an Eddy Merckx with all internal routing for brakes and gears for reference purposes.

3) the price they quoted me was more for the Swiss market, which is also irrelevant as it'll never sell locally. Why you might ask? The Magni / ICS-modified parts pop up quite frequently here in Switzerland (quite frequently being a few times a year). Given that they are labeled als ultra-rare by many and command a high price internationally (which they don't here in Switzerland), one can't really adequately compare markets. The target audience here is much too small and values different standards and goods.

4) the Swiss market commands very high prices for your average run-of-the-mill bike, but people don't collect bikes here that much (except for a few gentlemen). Bicycles theft is also quite frequent.

5) taking all of the above and many more into consideration, I'm asking an international and perhaps even more experienced audience as to their input :)

6) the rough figure was north of 3.5K, which doesn't mean much. it is just like going to the doctor. you always want a second opinion just to make sure :P