Great topic. I remember some very specific comments a professional conservator, Dr. Robert Faltermeier, who was kind enough to share information regarding this exact topic.
Regarding humidity he recommend iron containing metal works without organic material be kept at under 30%, but mix media (ie like most swords that contain iron, wood, and other animal product (leather, rayskin, etc) at 50% humidity. Lower that 50% might otherwise accelerate the drying, shrinking, cracking process of the organic materials.
Robert also commented he was not a fan of the famed Renaissance Wax because it contains microwax and polyethylene wax.
see listed ingredients:
Microwax has varying melting points.... potentially 40 to 80 centigrade.
In Singapore they put Renaissance wax on a outdoor sculpture and it ended up evaporating/ melting off.
And more importantly, polyethylene wax is insoluble in any solvent. So once applied the polyethylene wax can not be properly removed.
He recommended Cosmolide microwax or commercially available Tre Wax, a microwax containing carnauba which has a higher melting point and is more reversible.
A nice thing about Tre Wax too, is you can get a 12.35 oz (365ml) can for $13 USD versus Renassance wax you can get a 6.7oz (200ml) can for about $19 USD (not including shipping)
Reference & with permission, not promotion.
I would also point out his published article section:
and in particular the article on Silver Conservation maybe of particular interest to all: