Green’s Dictionary of Slang

to repeat oneself; to redo in an improved manner.

1907		W.M. Raine Bucky O’Connor (1910) 213: ‘That’s the ticket, York,’ derided Leroy. ‘Come again. Turn your wolf loose.’.
1922		M.E. Smith Adventures of a Boomer Op. 35: ‘Come again on that initial,’ says I.
1944		Cab Calloway New Hepsters Dict. in Calloway (1976) 254: come again (v.): try it over, do better than you are doing.
1950		in E. Cray Erotic Muse (1992) 323: I gave her inches ten and drove it on. / I gave her inches ten. She said, ‘Honey, come again! / Put your belly close to mine and drive it on.’.