DEPG Member and active volunteer Paul Tucker has recently been back
through his archive material and produced some excellent "decade by
decade" reports into the DEPG.
The 70's, 80's and 90's are detailed below, with the "naughties" to follow.

Paul has also sent data sheets on D1010 and D9526 detailing something of
their history also attached below.
DEPG History- The 1970's
DEPG History- The 1980's
DEPG History- The 1990's
DEPG History- D9526 Data sheet
DEPG History- D1010 Data sheet