That bicycle takes an ISO/italian/bsa headset to start with, In a matter of fact they came with a campagnolo strada headset. Now my questions...

The frame was prep already???

What headset are u trying to put in the bike??

Are u measuring in inches or in metric system??

If you are kind'a anal with measurements what you can do is just use a file in the fork crown race area, probably in less than 30 secs that thing will be at the right size, we are talking about centecimals of a mm in here.

If the frame was repainted or rechromed then is easy to figure it out that the extra stuff is coming from there because sure you have chrome or paint inside of the front tube.

The frame might need to be chased again, if the frame is new and never built probably never been chased, any descent LBS can do that but so far at leas the crown race is just file tiny bit and with a lot of grease will fit right in.

The cups you said 0.008 inches?? that's 0.2032 millimeters.. sincerely that thing will slide right in but I would take the frame to the shop to get it chased just in case.

Good luck and post pictures.