One of the things that irritated me about the extruder was the time it took to open the pump and close it again. To make it slightly less fiddly I replaced the lock nuts with a pair of threaded steel plates :-
I used Forrest's recipe for cooling fluid while drilling these. It worked a treat, I had no idea you needed cooling when drilling steel to prevent the drill from being burnt.
The springs I used first time around that came from an old CD player weren't quite strong enough but I found some better ones in the hinges of an A3 scanner I dismantled recently. Six of these held the lid open.
Here they are installed on the machine :-
I should be extruding again tomorrow!