Would no doubt have been airline specific but in addition to the VORs, DME,s ADFs, I'd expect to find Doppler and Loran (the old style with a small green cathode ray, oscilloscope-like device)
The lack of an astrodome does not preclude astro/celestial as there would have been a sextant aperture.
I believe they had a Smiths flight system linked to a Smiths autopilot.
Hope that helps.
p.s. Have you had a look in the one at Duxford?