CHGPF changing the CCSID of fields in a file.

We ran into a situation where a CPYF command failed because the from
and to file had different CCSID's and we had not included the *MAP
*DROP as part of the parameters. The from and to file were intended to
look alike which is why we did not add these parameters.

When researching the issue and determining how these files were
created, we realized that one of them was changed using the CHGPF
command. The format level identifiers of both the from and to files
were the same.

The QCCSID system value of the system we are having this issue in is set to 500
The source physical file is CCSID 37
The original file in QTEMP has fields that are at CCSID 37

When we issue a CHGPF command with the CCSID value set to *SAME

CHGPF FILE(QTEMP/TFEFA) SRCFILE(TESTBASSRC/QDDSSRC) CCSID(*SAME)               
 
After this command runs, the CCSID of the fields in the file changes to 500. 
I cannot specify CCSID(37) with the CHGPF command since i get a
message  CCSID parameter requires SRCFILE(*NONE).

One idea i have is to tell my client that they have to change the
QCCSID of the system to 65535.

Do i have any other option other than this to resolve the issue ?