The enemies of vintage gear are moisture, light, pests, and well-meaning over-cleaning. A stable room — moderate temperature, humidity neither damp nor bone-dry, no direct sun — does more for a collection than any product. Wool and cotton should breathe; paper should be isolated in acid-free enclosures; leather should be kept supple with conditioners intended for historic material.
Resist the urge to restore. Original paint, honest wear, and period repairs are evidence, and removing them erases information that cannot be recovered. Stabilize active damage such as red rust or insect infestation, document everything with photographs and notes, and leave cosmetic decisions to specialists who work with museum-grade objects.