Hi Edward,
I don't know what type of data you are sending to the LCD, but you need to consider the amount of memory you have available and the time to send it to the display. Your LCD routine will have you convert your byte data into two 4 bit nibbles, and then set the 4 individual output pins to correspond to the correct bits in sequence. This will take time and code space.
The customer will not pay you more for all this effort. I'd tell him that he should upgrade to a "better" processor, then put a SOIC package 16F876 (or even '877) on an adaptor board (like a Stamp or the Pic 10F "hobby kit") with the pin swap incorporated. You can impress the customer with the "latest surface mount technology" and save yourself a lot of trouble. At 1000 off quantities the board cost should not be bad. You could even include ICSP for field upgrades.

Robert G8RPI.