Thanks for the quick reply Jason. Unfortunately the vectrex overlays aren't configured like this by default. The documentation found on the internet (not this site) for using vectrex overlays sucks to put it nicely. I ended up modifying my vectrex.lay file so I could launch the game with proper overlay (where the overlay switch is the same as the rom filename). I have to admit, I was stupid for not RTFM but did see that you can use batch or cmd files instead. So I created a cmd file and placed it alongside my MESS file
ECHO OFF
SET GAME=%1
SET PREP=%~dp0
ECHO Starting %GAME%
%PREP%MESS.EXE VECTREX %GAME% -view %GAME%
And now it works like a champ.
I'm not sure if this would be helpful for anyone, but here's a sample modification I made to my artwork\vectrex.zip's vectrex.lay file.
Step 1 - see sample snip below. The "view name" needs to be the same as the rom zip filename. The bezel and overlay values are defined in step 2.
<view name="3dminest">
<bezel element="mine">
<bounds left="0" top="0" right="3" bottom="4" />
</bezel>
<overlay element="mine">
<bounds left="0" top="0" right="3" bottom="4" />
</overlay>
<screen index="0">
<bounds left="0" top="0" right="3" bottom="4" />
</screen>
</view>
Part 2.
Define the element name which links the above to a overlay png filename.
<element name="mine">
<image file="mine.png" />
</element>