COLOR-SKOPAR 1:3.5 / 50 front lens disassembly

Hello,
I need a little advice from someone with experience: I need to get rid of all the lenses of the mentioned lens (I think it came from a Vito II camera) because I need the Synchro Compur shutter and the front one is giving me problems: whereas other models I could see online have a pair of retaining lil nuts, the one in my hands has a scale in feet with just two little rectangular "holes", one near the "t" of "feet" and the other not far from the "infinite" simbol. I really can not guess how to unscrew front element. Any suggestion?

Is this a front element focusing lens? IF(big if) it is, there's sometimes a screw that works as an infinity stop.
With the stop screw removed it should unscrew.

yes, it is, and no, the screw isn't there on the "collar" around the focusing lens where i have found it in the past on other cameras, and i can not figure out where else it could be or how those two "holes" could do about it, if they do...

IIRC, the front element unit requires two special wrenches to separate the unit, one to hold the lower portion static and one to spin off the upper section. I believe, though I have not taken one of these apart myself, that once the front element unit is separated and the parts removed individually, you should be able to access the shutter. The shutter itself is a standard arrangement.

It's too bad you can't use the unit with the lens - the Color Skopars are really excellent.

First of all thank you for your answer.
The lens/shutter assembly came "as it is" from a "combo-bargain-ebayoffer" together with an older lens (a triplet from some old folding camera). This last one was really easy to work on, but unfortunately shutter is damaged.
So I moved to this second one. I need the shutter alone to complete a DIY 6*7 pinhole project and this one misses "T" pose but reaches 1/500 so I could even plan to use a flash... wow!
If I understand correctly, the special tool to hold lower part could be somehow replaced, but then: what is the correct verse to turn the upper part? clockwise or counter?

By the way I am curious myself to try one of this "older tessars" and sooner or later I will follow temptation and buy one of those lovely Vitos...

have a nice day!

Should be standard thread (counter-clockwise to remove). Rather than fabricating a precision tool, I have to wonder if you wouldn't have an easier time with a simple box camera shutter - they're a dime a dozen and virtually all of them have a B setting. That's what I did when I converted a Kodak Six-20 to a 6x9 pinhole. Or just find another leaf shutter.

yes, i was already looking for something else... your suggestion about any box camera as a source is a good one, I'll take a look! thank you