[FlatheadTed]

A 34 channel starts at 1,3/4 from the glass at the front .The opening is 10,1/4 from the front, its 9,1/4 from the stop screw in the channel ,On 34 its important for a 34 because it engages the rivet /roller that slides the glass back .yours is not 34 but some of it should apply to a 33 to .
ps its 9,1/4 from the stop screw not 9-3/4
and 3-5/8 from the rivet roller to the front