Yes, all 64s have fixed sights. The factory "adjusts" them by clocking the barrel a bit.
Tapered barrel 64s are fairly early in the run of 64s. Someone with a book will come along any minute here and tell you what year.
The most common (by a lot) barrel length was four inches, but I have seen and owned my share of 3" guns, and there are 2" ones all over gunsamerica right now.
Measure from the very front of the cylinder to the tip of the barrel, and then tell us what barrel length.
Also, what dash number? When you open the cylinder it should say "MOD 64-X" where X equals the engineering change.