Vintage Track Cog Part Cluster 3s 13 14 15 Fixie 3 Speed Fixed Gear

Vintage track cog set with 3 adjacent cogs.  Small cog appears to act as a lock ring threading into the larger cogs or onto the lockring threaded section of a track hub. Larger cogs thread onto the larger thread approx 1.378 x 24 portion of a track hub.    Good threads. 

Unsure of the brand. Or age.  Possibly prewar.