It falls under the category of badges and emblems, specifically hardware railwayana.
Vintage BRNS British Rail Badge Collectable Enamel Pin Badge (A5/33)
Collectable Enamel Train Badge SR 21C151 Winston Churchill Pin Metal
RAILWAY ENAMEL PIN BADGE EASTERN REGION B1 4-6-0 PIN BADGE
VINTAGE SE & CR C 0-6-0 NO.592 RAILWAY ENAMEL LOCO TRAIN ENAMEL PIN BADGE
Deltic nameplate badge, lapel Enamel pin Badge
Class 57, Restormel Castle, GWR, Night Riviera. badge, lapel Enamel pin Badge
