Looks like P0T09B? If so, that would decode to P- Muncie plant 0- built for the 1970 model year T- December 09- 9th day B- M21 close ratio because its a December build, it was actually built the prior year. So it was built Dec 9th 1969. Im going to guess your car is an early car?
The body was assembled on the third week of January 1970. Your trans is dated Dec 9th, 1969. So the trans and the body are a little more than a month apart. The trans being the earlier built. So it would appear that it may be the original trans for the car. It should have the VIN stamped on the case just below that "P" number.