the true speed of Tri-X is a personal thing, it depends on your developer/your developing technique/ etc., etc., etc. On bright days I shoot it at 200, overcast and rainy maybe 400. Most of my Tri-X is souped in Xtol or D76  1:1, YMMV.
the first one is rated at 100 in shaded light: 
http://www.rangefinderforum.com/photopost/showphoto.php?photo=50627&ppuser=489
This one was rated at 800: 
http://www.rangefinderforum.com/photopost/showphoto.php?photo=35623&ppuser=489
I find Tri-X to be one of the most versatile films around, good luck!
Todd