Help find proper headset/what is this frame??

Trying to find the proper integrated headset for this frame. It seems to be the campy/bmx style 45×45 w/ same size on both top and bottom but the only headsets i found have 41.8 cartridges and it turns out Its like 1mm off (see pic)! So i need 41mm bearing cartridges, which i can find, but not a full headset.

I was trying to figure out what the frame is to look up some specs but had no luck. Let me know what you think!! Track frame with flattening top tube style.

Any help much appreciated! This has been a head scratcher!