Just made a laser finder, by looking at the photos it's self explanatory.
I mounted a 5mw laser module in a ebay laser mount and bolted it firmly but not tight to a dovetail clamp that I just clamp it to the Vixen dovetail bar.
Because it is firm I can move it up or down and sideways to align it.
Added a 3cell AA battery pack with a on/off switch and Bobs ya uncle.
http://i40.tinypic.com/20qmc2f.jpg
http://i44.tinypic.com/2akigqe.jpg