I am a CSD with 32 year service, I now work 50% my P60 for 2009 - 2010 was 21,703.00 after tax..
Using an online calculator such as "The Salary Calculator", doubling the monthly take home pay and assuming 8% pension contribution, then your gross salary was £68,400 per year.
A lot of assumptions I know and maybe £70k is over the top - a bit like saying all pilots earn over £100k per year