Thanks to Raymie for posting the MARMOR ID (below) in May, this mystery is solved.

XHFX-4 Morelia, Michoacan has not been IDed here in years, but I do have XHFX ID material on tape.

The poor-quality XHFX ID photos show the upper left corner of the screen, which was recorded on
July 13, 2006.

I never could figure out what the very thin first letters on the second line were until I looked at the ID
Raymie posted. The bold MOR was easy.

The ID reads:

XHFX
MARMOR

Click image for larger version. 

Name:	xhfx4marmor2015.jpg 
Views:	51 
Size:	9.4 KB 
ID:	18017 Click image for larger version. 

Name:	xhfx407132006b.JPG 
Views:	51 
Size:	63.9 KB 
ID:	18015 Click image for larger version. 

Name:	xhfx407132006a.JPG 
Views:	51 
Size:	72.8 KB 
ID:	18016