In 1981 - 2 Standard wagon built two distinctive designs of mineral open wagons on underframes reclaimed from APCM vans (see http://paulbartlett.zenfolio.com/apcmvan ) as well as the clays (see http://paulbartlett.zenfolio.com/chinaclaypra ) It is unclear whether any of the PMVs went into traffic before conversion to air brake as PMA. Some of the high conversions went on to become China clay PRA. Collection includes details