Hi Clint. I don't think the 203rd had any Dinahs; "j.aircraft" have these NAVY units with some: 151 / 171 / 202Ku. The link is Rene Francillon's list for ARMY Dinahs, I can't see any links to 3-201 though. The 3rd. Okazaki AG used "3" plus number but were a Special Attack unit.
There are 2 photos of Dinahs marked "4-007" and "4-008" earlier in 1945 with 4th FCS (I think an Independent Chutai) presumably Mk. IV serials 5007 and 8, if so they would be 2 of the 4 shipped to the US from Yokota. I think Yokota is a reasonable location for 3-201 as the 8th. CCs was there from Sept. to 1946.
https://boxartden.com/reference/gall...2-_Page_10-960
Nick