Struggle with tool holster measuring

[kwrcst]

Hi all,

im trying to make a belt worn holster for a leather an and light and plan to wet form it for retention. Fog the life of me, I can’t figure out the top piece sizing. I have the base plate how I want it but the top either is too tight to get in or I can’t get it to line up because the pouches/slots for the tools are too far apart. I’ve tried laying strips of the same weight leather over and marking the stitch Lines like I would for a pistol  but my layout is still wrong. 
 

How do you all measure?  Do you make the right stitch line for tool 1 and use that for the left stitch line for tool 2?  I’d like to have about 1/2” between the 2 lines to put a key ring between if I could. 
 

thanks

 

kelly