Thank you both for your help! I'm happy to direct wire the socket, but I wasn't sure of the gauge or force required to push the wires in. The manual helps and obviously a solid conductor is best. I will play with it...
On the side: I find that even though the inverter is claimed to be pure sine wave, my torroidal transformers buzz when connected. I understood this to be a sign of a DC offset in the AC waveform, which causes the transformer to saturate - clearly not a good thing! Any suggestions, please? Thank you.