Here´s the final stage of painting:
As said, I added an overall wash of yellowish olive (Revell Khaki Brown, to be precise) over the model and dabbed off any huge unwanted puddles before they could set. Then, I painted a fine dark grey wash into the recesses. Finally, I painted some black wash around the vision blocks and the turret MG.
After that was dry, I painted the tracks in Vallejo Tracks Primer, later to be very lightly drybrushed using Revell Aluminium. The antennae were painted dark grey (all dark grey references are to Revell Panzergrau). Some detail painting ensued (headlights, not visible in these shots, plus markings).
Finally, I took a blunt metal piece to scrape off the paint in places to recreate that chipped look. They look well worn now, but not overly shabby, IMHO.
A final composite image showing tank 144 from some angles, and the maximum elevation of the guns: