Congrats on your new loudspeakers. They look fabulous. I too had the same issue with my '93 Chorus 2's, at first. However, my ears has since acclimated to the brightish tonality. Presently, I'm not bothered by it any longer.
As a matter of fact, the other day I visited a poker buddy's house and quickly noticed the difference between my tube powered C2's and his vintage Fisher system. The longer I stayed, the more I yearned for the clarity and pure power of my own.
Give it some time. If it continues to be an issue then follow Mr. Moray James advise. Believe me you, he knows what he is talking about. Several things I did do, was adding a couple of ounces of weight to the rear passive radiators, spread them apart about 15 feet, toed them in a bit and dampened the horns, as well. It was cheap and effective, and yes, it was Mr. James advise.
I'm keeping mine stock for now. Why bother at the expenditure if it is not broken to my ears. I figure, let well enough alone. However, It's good to know that I can upgrade in the future, if need be.
Good luck to you, sir.