Can anyone recommend a 40 pin replacement with the same pinout

Search in the Keil device database

http://www.keil.com/dd/parm_search.asp

for chips that have the speed and features you actually need (e.g. do you use both serial ports) and then sort those by package and pinout. The likelyhood of a different pinout is only slight. With the exception of the 2 UARTs Maybe a Rd2 would do.

Erik