The 239 is a 'Scout' engine and was made with a unique Bakelite-bodied motor with a unique reversing system. They were low-end entry-level locomotives that were known to run erratically. They were not really made to be serviced, although they could be.
https://www.tandem-associates.com/lionel/lionel_trains_239_loco.htm

The original transformer may have been a 1073 which, at 60 watts, should get the loco to run.
https://www.tandem-associates.com/lionel/lionel_trains_1073_transformer.htm

Use the AC terminals on the 4060 transformer you have.


Larry