Steven, when you say the brakes are still not tight enough do you mean
there is more pedal travel than you would like?
Try this, engage the handbrake a bit, not enough to stop you, but enough
to get the rear shoes touching the drum. Then try the brakes. I they feel
better, then the rear brakes need adjusting.
The rears are supposed to be self adjusting, but a manual adjustment now
and then is better.

Alistair