Hi Peter,
You might also want to look at the differential. There are some spacer/thrust bearings between the gears that can wear or crack and fall out. The characteristic 'click' occurs when the the driveline goes slack as you decelerate and stop. A soon as you hit the gas, the gears move outboard to take-up the space and hit the housing creating that sound.
Early cars the washers were a fibrous material, which more often failed and fell out of place. Newer thrust washers were brass, as are the current replacements (Moss part# 267-140) and still cheap at $4.39US each.
Replacement requires the differential case be opened and the axle shafts removed. There is a way to install them without removing the gears and carrier, but at this age I might suggest checking all the gears, shims and bearings. Also, with the axel shafts removed, I'd also advise to replace the outboard bearings, seals and the rear brakes, since they will have to be taken apart. The axel itself need not be removed.
Hope that helps you.
Safety Fast!
Art