Very simple shirt studs.

[Noble Savage]

I recently came across this set. Are these for morning dress, from a time when studs were worn with such?

[Frog in Suit]

Just a guess but these look to me like a complete range of studs for various types of shirts, presented as a set.
From left to right: two back studs for all types of shirts (or a back stud and a front stud for a soft collar – hard to say as they appear to be the same length --, third from left (“dress collar” – whatever that means, perhaps a wing collar --) looks like a front stud for a soft collar, the last three being what they say (I would guess that “dress front” refers to a wing collar).
Alternatively, from left to right: a (universal?) back stud and a range of front studs for all possible collars as described
I only wear soft detachable collars; my back studs look like the two specimens on the left, the front ones like the “dress collar” one, except that mine have a mother of pearl base with the shaft in brass with a tip that swivels.
Why not show this to New & Lingwood or any other traditional shirtmaker and ask them?
Frog in Suit

[Concordia]

So in other words, studs for attaching collars only, not for wearing on the shirt front.

[Frog in Suit]

So in other words, studs for attaching collars only, not for wearing on the shirt front.

Yes. I think they are purely functional, not meant to be seen or to decorate a shirt front, except, perhaps, the two rightmost ones but I doubt it: they are as plain as the others.
Frog in Suit

[Noble Savage]

They would simply look like a plain version of these:

[Frog in Suit]

They would simply look like a plain version of these:

The two on the right, possibly (but why only two?). The others are collar studs.
Frog in Suit

[Noble Savage]

The two on the right, possibly (but why only two?).

Most dress shirts take two studs that show on the front.