in fact the OC-10 is very bright in sound and your Arcam seems to be one of the most "analogue-sounding" CD-Players ever. I have an Arcam Alpha 5, two AT-OC7 cartridges and a NAD PP, so I guess I know the results of comparing your TT and your CD-player...
Fiddling with VTA and Overhang won't help, the troublemaker is your Phonostage. The AT-OC10 works best connected to a matching transformer (more than 20 Ohms). A MC-Preamp should have a load resistance of more than 150 Ohms for best results.
The AT will still be bright, but with "good" amplification you have a great pickup with wide stage and lots of dynamics. Don't call it bright, call it clear and crisp
If you still don't like it, just sell it to me. I could also offer you a Shure V-15III in exchange