Which preposition to use with ambrotype

in Occurrences 2%

I went to the "little" war; and of her I carried, as I marched, an ambrotype in a closed case, which I had obtained deviously.

of Occurrences 2%

They were just alike; there were the two crooked marks upon each, speaking as accurately as the most highly finished ambrotype of the day.

Which preposition to use with  ambrotype