Buying a used Oracle Delphi Mk_ ?

Any comments on what to look for and/or to avoid in a used Oracle - or whether to look for or to avoid a used Oracle in the first place? The idea would be to pay a modest price and then to upgrade gradually as the budget welcomed, enjoying the music in the meantime.

Our system hasn't been complete in over a decade, as we moved around too much to 'do it right': A humbly exquisite little modified Dynaco 70 in triode is all there is of it at present; in the past it included a Walker turntable with Audioquest (which we thought were listenable under the circumstances) and Spika T-60 speakers (which we adored). Thank you all for any input you think relevant.