The "Lacey" Polo Breastplate

The best way to take care of this breastplate is to clean/oil the chest strap and girth straps regularly. This means an absolute minimum, of once a month, for a deep clean. Which includes; the old fashioned soap and a damp cloth to remove the dirt and grime, particularly the nappa backing, followed by adequate sun to ensure leather is dry, followed by a conditioning of the leather. Regular cleaning of the soft backing will ensure minimal cracking over years of use. Once this cracks and dries out, it will cause rubbing on the chest. The backing will only need a light conditioning, not oiling. You can oil the leather, however avoid the backing as it is a chrome tan leather.
The wither strap should also be wiped, cleaned and conditioned at the same time.
The easiest way to clean the laced sections is to lightly put a clean tooth brush over the lace, this will lift the dirt out of the hard to reach areas. Once clean, condition the lace last, with small amounts of conditioning cream at any given time. This will avoid a build up of grease and a "glue" for all future dust.

By doing a deep clean at least once a month and reducing the built up of dirt and sweat at the buckles and any dee rings you will get longer lasting use. Regular cleaning ensures sweat build up is kept to a minimum which will help avoid leather rot, drying and cracking of the leather and ultimately the leather snapping/breaking. Failure to meet cleaning requirements, will result in the void of warranties or insurance claims.