oops, sorry - it seems I understand now. My original routines are for checking of program code, not for data transmit.
So it need just to rotate bytes to right. I think it is not hard to modify those routines.
Only one question: must they produce the same result to be compatible with original ones? By other words: we have data array and two bytes at the end which is CRC of array, calculated with standard (original shift left) routines. Now we transmit data over RS-232. UART receives them and collects into a buffer. Then we call the routine which checks CRC with the new (shift right) algorithm. Are you sure that such routine obtains the same CRC (zero-result) as original one? I doubt. Due different check direction it produces non-compatible result.
Summary: both transmitter and receiver must use the same routines/algorithms. CRC-16 with 0x1021 polynome is common-used standard. If we change check direction then we go out from it. Are we need to do so?

Regards,
Oleg