Got my new wheels last week and have been test fitting them to the car. The prior owner installed a Master Power Brake (MPB) 4-wheel power disc brake conversion kit. Although I'm not a fan of MPB conversion kits, I don't have it in my budget right now to change it. The front wheels fit perfectly with no mods needed. However, the rear wheels were coming in contact with the brake calipers. So I had to grind off a little bit of caliper housing material; maybe about an 1/8", but afterwards I have just enough clearance. Regarding the center caps: Got mine in today. They measure 2" tall (perfect). As far as the retainers, I decided to take a different approach. After looking at them, I concluded it wasn't necessary to cut off the tabs to get them in the wheel's center hole. All I needed to do was to bend them just enough to get them in. With the tabs remaining, it provides a bit more centering and support for the cap and retainer. I've included photos showing the bend angle of the retainer tabs, and the install. Hope this helps for anyone looking to take this route. BTW - the wheels are absolutely BEAUTIFUL, and the center caps are very nicely made repros. Thanks for all the support.
