This kit contains a set of Stanley's proprietary thread fasteners and contains all fasteners except lateral adjust lever and rivet assembly, Y lever and mounting pin assembly and frog adjusting engagement clip.
Where there are metric equivalents used in current model planes duplicate metric fasteners are included in this kit. For most users these will be of no use.
For the majority of the long period when Stanley planes were the dominant brand Stanley used a unique, proprietary thread standard. At some relatively recent time in the early 2000's Stanley began using metric fasteners for some of the fastening needs in their hand planes. It appears the only applied logic was that those parts connecting to the frog remained Stanley threads and the remainder went metric.
Stanley Bailey Exploded Parts Diagram