Congratulations on your historic footwear! There are some steps that you can take to maximise the life of your footwear and prevent premature wear.
Historical Turnshoes – leather sole
Dry
It is critical that you allow your footwear to dry after use. Prolonged damp does awful things to leather.
Try to dry your footwear in the shape you want to find them. If they dry in a squashed form, they’ll stiffen into that shape when dried.
Do not pack wet shoes into a plastic bag. Pack in a breathable bag and attend to them as soon as possible after events.
Clean
Once dry, any mud or soil should be brushed off, then the leather wiped clean with a damp cloth. Leaving mud on the outside of leather will draw out leather conditioner and add abrasive particles to the surface of the leather.
Condition
Once the leather is dry and clean, wipe on a heavy leather conditioner (eg dubbin), rub in with hands or a soft cloth, allow conditioner to absorb and then buff off any excess. For turnshoes, condition the upper and the sole. Leaving your conditioned footwear in the sun or other warm spot can help the conditioner to absorb.
Repeat conditioning, if possible, until no more conditioner will go into the leather.