Larry, I certainly don't consider enlarging the suspension mount bolt holes to 1/2" "mutilation", if it was done as part of an overall improvement. Obviously, Dennis Q.'s bushings do indeed have a 1/2" ID and metric OD. I can see Dennis doing this because he's always complaining about the Pantera's junk metric hardware.
FYI, Dennis advises changing the steering arm to spindle mounting bolts from M10 to AN7/16". Apparently, there's a problem with the M10 bolts breaking!!! As a long time Pantera owner, that's news to me! On the other hand, there's likely no one who's seen more Panteras than Dennis, so if he says it's a problem...
Shashi27, there are two obvious, easy solutions to your bushing problem. The first being, just buy a new set of bushings from Dennis; the same ones as on the car now. The second being, buy whatever bushings you want and ream the metric center hole out to 1/2". As the amount of material being removed is so minimal, I can't see it causing a problem.