This page, covering both racing at Charterhall and a list of known vehicles driven by Jim in 1958 is not fully populated at present however it could be that this lorry is the one used in 1958 with the Border Reivers D-Type.
Registration number SH 8693, the Edington Mains lorry of James Clark & Son. It looks like a Bedford M type.
The advertisement from the BMRC Bulletin of December 1958 (Vol3, No.9). The new owner of the D-Type was reported in Vol 4, No.1 as Alan Ensoll to replace his Jaguar C Type sold to Tom Candlish. The D-Type was registered as TKF 9 and the TR3 as RSC 190.