hello can any one help? have a grinding on over run and then again on power take up, sounds like a worn bearing. not sure of exact location gearbox or rear axle. is this a common problem?

T reg.......................... 1999 hi 1978-79 version of T reg, T at other end of plate

Can any one help confirm year of build of my series 3? trying to get historic tax, date of first reg is 3\01\1979. but dvla have it as being built on 29\12\1979 . so has being driven, taxed etc for nearly 12 months before it was built. Thanks