So putting aside the Austro Daimler SLE that sort of frustrated me a bit...I moved onto my rare bird, the MBK (Motobecane) Atlantique that I have found 0...zero...nada...zip information on. Trying to get a decently durable headset on it since it is presumably an Xcross/hybrid/gravel grinder type bike.

I measured 40mm of stack height available, and do not mind adding spacers on. It seems to be JIS, which means 30.0 inside diameter, 27.0 crown race and presumably English threading for a 25.4 steerer. Sir Sheldon says that these were common on lower level Asian bikes, but this one is definitely made in France. Is that unusual?

I do not feel confident making the crown race 26.4...

--I am a fan of Tange, but the Passage and Levin are too short and I do not wish to cut the steerer (I would rather add spacers, or am looking for 38.0 stack).
--I have seen several BMX headsets that fit the profile; is there any difference in BMX headsets?

Options on the bay
--Fits the profile but looks rickety https://www.ebay.com/itm/27107848551...Bk9SR9Dy55eHYQ
--A black Levin with BMX specs? https://www.ebay.com/itm/19544725761...3ABFBMho3OmIdh
--What I WISH would fit (26.4 crown race) https://www.ebay.com/itm/27453493760...Bk9SR4iNzpiHYQ

YST hybrid? https://www.ebay.com/itm/30372486636...Bk9SR9S7gpmHYQ