"$1,300 for a few vintage Rolex parts. Crazy -- but this time next year, crazy will have been a bargain."
Yeah. If you can find one at all a year from now.
I bought two sets 1575 GMT center wheel with cp and hour wheel, without any GMT calendar wheels (pn 8034) a few years back and they were somewhere around $200 for two sets. The 8034 GMT calendar wheel is hard to find today. The $1300 kit is basically enough for a conversion plus you may need to space the calendar ring up a little bit.
Why?
Because the GMT calendar ring is about .10mm thicker than a regular 1575 date ring to make space between the 24 hour wheel and dial. A friend cut some 4 mil (very close to .10mm) circles out of Mylar on a decal plotter that sticks to the ring to raise it up. Works fine and saves $$.
I did not use an 8021 GMT calendar wheel on the 'shortcut 1655'. The GMT kit for $1300 on eBay has the 8021 calendar wheel but does not have a GMT calendar ring (pn 8037).
Sometimes they work Ok without the thicker calendar ring and sometimes not.
After proof reading all this mumbo-jumbo a couple times, it sounds like 18 month old kid gibberish.
An 18 month old kid that's been hittin' the prescription cough syrup.
Typos are free.