Thanks Mad Dog! The tally now is 29 rifles:

1050 (.35)
1737 (.30)
1805 (.30)
1842 (?)
1977 (.35)

2514 (.25)
2592 (.30)
2628 (.32)
2838 (.35)
2914 (.35)
2973 (.25)

3056 (.30)
34xx (.32)
3527 (.35)
3684 (.35)
3788 (.30)
3856 (.35)
3950 (.35)

4011 (.30)
4073 (?)
40xx (?)
4209 (.35)
4290 (.30)
4343 (.25)
4490 (.30)
4837 (.32)

5201 (.30)
5302 (.30)
5594 (.32)

That breaks down to three in .25 Rem, ten in .30 (or .30-30) Rem, four in .32 Rem, and nine in .35 Rem.

Plus there are at least two more that we don't have serial numbers for: The complete gun listed on GunsAmerica and the barrel & receiver listed on GunBroker. I've emailed both sellers but have not heard back from either.

Peter