Looks like we have found another transaction, this involving the Cubs and Mets organizations in 1965.
Bill Wakefield had an 'okay' season for the Mets in 1964, but found himself in AAA at the start of 1965. Starting at Buffalo, he suddenly shows up at Salt Lake City, a Cubs AAA affiliate, with no reason listed why.
Checking The Salt Lake Tribune from July 11, 1965 we find the following:
AHA! Checking with Jack Warner finds him going to Buffalo in 1965! So we have a trade of Warner to the Mets for Wakefield.
Seems Warner was sent out in 1965 from the big club as the Cubs recalled Billy Hoeft: Chicago Tribune of June 30, 1965.
So his refusal to report resulted in a trade to the Mets.