Its mostly wind instruments:
HAYNES, Bruce. A history of performing pitch: the story of'A'. Scarecrow Press, 2002.
writes on page 4:
In terms of numbers, I was able to consult the pitches of many
surviving original instruments, thanks to a grant from the Canadian
Social Sciences and Humanities Research Council. The present book
regularly refers to this information, which is included in summary
form in the appendices; these list the pitches of some 127 cornetts,
28 Renaissance flutes, 292 traversos, 317 recorders, 70 clarinets, 540
organs, and 13 pitchpipes, for a total of 1,387 original instruments.
The appendices include only instruments whose reliability I trust. Of
these instruments, about 222 are Italian, 208 French, 544 German,
192 English, 11O Dutch, 77 Belgian, and 31 Austrian.
A change in temperature from 20 to 24 °C will result in a pitch change of 11.7 cent, (PISANI, U. Effect of a Local Temperature Change in an Organ Pipe. Acta Acustica united with Acustica, 1976, 35. Jg., Nr. 2, S. 132-136.) which is not that much, but there are other factors, e.g. wood may change over ages.
Bruce Haynes gives a number for pitch pipes compensated for wood shrinkage:
To compensate for wood shrinkage, pitches given here are 5 Hz lower
than pipes presently play.
But not only wind instruments play a role, e.g. the tuning forks of Handel and Mozart are preservered, but
The problem with tuning forks is to relate them with assurance to a
particular place, time, or usage. Unlike pitchpipes (which are often
stamped and which give note-names), forks offer few clues to their
date of manufacture and use, or even where they originated.
(page 31, HAYNES)
And even some stringed (e.g. not bowed) instruments can be taken into consideration because of the physical properties of the used strings:
Wraight found that the most common string-lengths for the note f2 of
Venetian instruments made between 1523and 1594were 235, 246, 255, and
265 mm, particularly 235 and 265 mm, which would notes a whole-tone
apart from the same key of the keyboard. Since at that time there were
two important Venetian pitches a whole-tone apart, mezzo punto and
tuono corista, it is logical to associate the two string-lengths with
the two frequencies (about 464 and 413 Hz, respectively).
(HAYNES, p 23)