According to Yeadon, 65023, 65016 (photo) and 65020 were unlined black in 1948. 65015 was the first J2 to be lined in Sptemeber 1949 with no lettering or emblem on tender (as above). 65019 (photo), 65016, 65018 and 65020 were fully lined with small emblem in 1950. 65022 (photo) was ex-works in plain black without lining in June 1951 and was followed by 65017, 65023 and 65015.
There is some variation between locos regarding retention of piston tail rod platforms and location of handrails and vacuum pipe.