Nice job Tarzan it looks great, hope that Jane is suitably impressed ;)

Regards the lubrication for it, if you ask ten people you'll probably get ten different answers, and it's probably best left until you have a working key for it, which I'm sure means oldlock will sort it out for you then anyway.

If it was mine I'd probably only give it a few strategic puffs of powdered graphite, as it'll work miracles once it's worked in with the action of the key and knob. If there's any sign of resistance of the latch once fitted during use, then perhaps consider a few thin smears of white grease on critical friction points only, but even that's best avoided if it isn't needed.

It's going to look mighty impressive on whatever door you decide to fit it to, you will need to consider a strike plate/receiver for the frame if you haven't got the original.