[Vecchio Vespa]

I used to wear a lot of Press shirts. I found them well made. However, the Press fit has always seemed to be on the trim side. The collars were close to perfect after several years of being too short but still lacked the elusive roll of ancient memories of Brooks and the standard at Mercer. As their prices have moved up, even though Mercers cost more, I concluded I would rather have fewer Mercers than more Press. If you pull the trigger I would be interested in your assessment. If you go OCBD at Press, the pocket flap is definitely a love it or hate it thing.

 

[Vecchio Vespa]

Zip, if you do it yourself.
But since I'm unlikely to move you in that direction, let me mention this...

I believe you're talking about moving the buttons up, not down or over, and thereby exposing the area where the button used to be, so consider first removing a button from a shirt that's not particularly important to you to see what's left after it's removed, meaning any sort of holes that cannot be covered through pressing with a hot iron.

All shirting material, no matter the quality, is as you know relatively thin compared to most other fabrics, so care in removing the buttons is paramount. Often, inside the shirt behind each button, will be a button-sized piece of fabric that thickens the area where the button is attached so it can't easily pull off the shirt. This is good because when you remove the buttons there will be less chance of cutting the shirt. Good luck with this.

(As a complete aside, I am the opposite of most here. Do not care for the bell-shaped roll. I have always liked the look of a collar when using a collar pin, not because of the pin, but because of what it does, hold the points of the collar down tight right up to the tie knot. Because of the like of that look, I have a few times sewn a button down collar to the shirt halfway up the point, allowing only space for the tie to pop through. Different strokes, etc.)

As regards your second aside, I like the bell but also the look you describe. For me the love of the OCBD is all about the comfort. Billowy fabric getting softer and softer over the years is lovely. I hang onto them long after the collar has been turned and frayed again.

 

[Vecchio Vespa]

O'C Unlined/Unfused, the regular, or the regular heavyweight for the better collar roll? Looking to add a few more OCBDs to the wardrobe and want to try all of the "good" options.

They are lovely shirts, but the collar roll of Mercer is unbeatable.