DD150510 is a handwritten list by Delia of corrections to be made to some of the tracks in Electrosonic.
If Delia's codes correspond to the final album's track listing, these would be
K.P.M. 7½ mono! ------ -------- ..B4 ..C3 ..B2 needs overdubbing - lower line too loud - doublet thirds too quiet: bad edit shd. bb more perc.. less decay ..B1 out of time - look at score - bass ..A8 - check bass line - drops out on [Spendors?] ..A7 ....A6 ...A4 ...A2 - check treble - drop out on [Spendors?]