[TR] TR2/3 Windshield Washer Pump question - image link added

[Carl TR]

Image of the needed washer pump...
http://s1001.photobucket.com/albums/af136/cfmtr3a/Information%20Items/?actio
n=view&current=WasherPump.jpg 
it looks like it is 5/8 -3/4 inch.

Does anyone have the correct pump knob unit and can measure the hole size?
I have several non-original ones and can mount one temporarily but I want to
make sure the hole isn't different.  

Thanks
Carl