Not being an expert on the Revision 'D', I'd say yes - remove anything not original *if* it conflicts with that CMOS of yours. I see the circle, but did these really come with a coin styled battery and not a NiCad? Guy might have been thinking he'd limit the recharging current when he replaced the original with a coin shaped lithium.
I guess if it works the way you have it, I'd leave it then. Looks pretty clean, but perhaps traces are bad somewhere, which is another reason he added the resistor? Hard to tell.
