Rolex Extra Prima: Difference between 666 and 663?

[Sandwich]

I've got this movement. Is this a 666 or 663 or something else, and what is the difference? The top plate is about 36-37mm diameter... perfect for a Panerai dial! This or similar was used in some early prototypes, right?

Rolex Prima.jpg

[binbin]

At the beginning of this thread there is a photo of the prototype you may be talking about.

viewtopic.php?f=8&t=1761&start=10

[VanSong]

I've got this movement. Is this a 666 or 663 or something else, and what is the difference? The top plate is about 36-37mm diameter... perfect for a Panerai dial! This or similar was used in some early prototypes, right?

Rolex Prima.jpg

Interesting find! Does look indentical to the movement pic taken from the Panerai Museum from Binbin mentioned thread. I think the only difference with your movement compare to the Museum movement pic is the Regulator.

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[straps68]

I've got this movement. Is this a 666 or 663 or something else, and what is the difference? The top plate is about 36-37mm diameter... perfect for a Panerai dial! This or similar was used in some early prototypes, right?Rolex Prima.jpg

Interesting find! Does look indentical to the movement pic taken from the Panerai Museum from Binbin mentioned thread. I think the only difference with your movement compare to the Museum movement pic is the Regulator.

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Actually, if you look close, the regulator is the same, however, [mention]Sandwich[/mention]'s movement is missing the "swan neck". It is a very beautiful movement!

[Yoda]

I am very sure that what you have there is a Montillier calibre and it is the 663. I am not familiar with the 666, but that may very well be made by Montilier as well.

I helped a member of HF with one of these, he needed a stem, that's why I know what it is. As already written, the swan neck spring for the regulator is missing on the movement in the picture.

My supplier had all the parts for these when she was still in the business, unfortunately she sold and retired in September 2018.

[Akvanautas]

Had one of these. Very beautiful movement but if you need any spare parts for it..such a pain in ass to find anything

[Sandwich]

Fortunately it runs well and is missing only the swan neck. Now what to do with it... I think a 2533 build is in the cards.

[Yoda]

Has it been serviced? It looks a bit tarnished.

Anyway, how does this swan neck look?

I can ask around when I know.

[Sandwich]

It hasn't been serviced and definitely needs a good cleaning, although it runs smoothly as is. A replacement swan neck would be nice, if you can find a swan to sacrifice....

[Sandwich]

I found this picture of one with the swan neck. Is it a hard part to make if an original can't be found?