20 Flanged wheel, No pulley section, one-part pressing, 4 holes, standard-type boss, Single Tapped, o/a diam 1 3/8, 35 mm, ¼" 6.25mm flange, stamped circular Meccano thrice, set screw though unlikely to be the original. This interloper has been in the family since the mid 1950s and was very tarnished so I cleaned it up before comparing it with the OPM. Clearly it is solid brass so why does it have signs of a brass finish coating clinging in the lettering?