Hey guys, thanks for the input...it's much appreciated. I think I have this sorted out now.
I took the bass and bridge to the luthier yesterday, he says it will not be a problem to replace the HMV with the vintage style bridge. In fact, when we were looking at it and laid the vintage style over the existing bridge it looked as though the mounting holes for the vintage might actually fall BEHIND the ones in the HMV, which means he could simply drill 5 new holes and not even worry about filling the old ones.
That would be fine with me as the old holes would be covered by the plate.
I'm really excited about getting this new bridge on there, I just dread changing strings with that HMV. That thing is a solution to a problem that didn't exist as far as I'm concerned!
Not only will I have a far more practical bridge, I weighed both of them and the vintage is 3 oz as compared to 6 oz for the HMV. I have become like one of those crazy hot rod guys who takes the seats out of his car to make it as light as it can be. I even pulled out the metal string ferrules in the body for the string-through thing (another useless "enhancement")
I know...OCD...but those things and the difference in the bridge shaves a quarter of a pound from the weight. My aching old back can feel the difference!