I have a few Guilds with the DiMarzio made XR-7s and find them to be very clean, especially when you coil cut them, but, although very clean, they distort very well also, You can see 3 versions of them. The early ones on the back plate say DiMarzio Made IN USA, the next version have the DiMarzio ground off so that they just say Made In USA and the final version say Guild XR-7 with a part number. All have the dark gray colored coil tops rather than black. Most have silver colored pole screws but some have gold screws.
Have fun,
tonepoet