UK GDP by Income
First, for the breakdown of GDP by category of income, we have ONS data going all the way back to 1955:
The relevant series used here are CGBZ, DTWM, CGBX, CMVL and YBHA. I think Tim is correct to note the (slight) rise in other income (which includes income from self-employment, so-called “mixed income”) and VAT are the significant secular trend.
For the split of “compensation of employees” between employers’ National Insurance contributions and wages, we only have data from 1987:
The relevant series are RPCG, RPCH and again YBHA for nominal GDP.