So, I'd like to create a template texture to use as a positioning placement for future tramp stamp tattoos at the lower middle back of v4's back. Basically, I'm asking texture artists for advice or a possible helper file of the best area, x pixel by y pixel, to put this marker as a photoshop layer so when I create tattoos later, I can split them in half and fit them correctly onto v4's weirdly UV mapped backside.

You can either send me a reply here or as a site mail.

Thanks!

Is the seam guide thats available not sufficient for placement . ? 

Where is said seam guide?

from DAZ.  The templates can be downloaded with the models

On the product page for V4 base there are the texture template for download. Further down the page is Sultans Seam Guide. Thats the one you want.

http://www.daz3d.com/i.x/shop/itemdetails/-/?item=4783
in the Resources and Information section. 

Seam guides here >> http://www.daz3d.com/store/item_file/4783/v4SeamGuides.zip

You can apply the seam guide as the texture to see exactly where the template is on the figure. 

That should help a bunch. Hopefully. If not, I'll repost here. Thanks, folks!