These were in deep storage at ITN and were then fully serviced and upgraded by Red Hill Audio.
I have not found the list of all the work Red Hill Audio did but will look harder.
I only remember the fitting of big BHC Aerovox psu caps and Elna Cerafines.
Then the active parts were serviced and uprated by a BBC technician:
4x Part Ex DADA Electronics modified Quad 405 MKII boards (£50 ea.) – £200.
2x Power Leads and accompanying custom fittings (XLR Delete) (£15 ea.) – £30
2x Axial Electrolytic capacitors 63v 220uf (£3.80p ea.) – £7.60
2x Blue LED Mods (£5 ea.) – £10
2x Mains isolation capacitors (£8 ea.) – £16
8x Tantalum Capacitors 25v 15uf, 35v 1uf (£1.75 ea.) – £14
10x metalised plastic foil capacitors 100v 6800pf, 250v 47nf, 100v 0.1uf (£1.50 ea.) – £15
4x metal foil wind, high accuracy capacitors 250v 820pf, 250v 220pf (£4.60p ea.) – £18.40p
2x BCY71 Transistors (£2.50p ea.) – £5
4x BC414B Transistors (£4.20p ea.) – £16.80p
2x 2N2484 Transistors (£2.50p ea.) – £5
8x New rubber feet (£1.20p ea.) – £9.60p
2x variable resistor knobs (£0.60p ea.) – £1.20p
4x 5-Pin Neutric XLR’s (£6.80p ea.) – £27.20p
2x 1.7M 4×1.5mm core speaker cable (£3.75p per meter) – £12.75p
Chassis are not a matched pair.
Cables included.
I will not recoup what I spent on these but offers accepted.