From UK Rail Gen on Yahoo:
This working runs on Friday Only. It runs with 31+Mk2s+31. It may also run on other days to cover DMU shortage and on Rugby Days to run as an extra service.
5O98 11:25[FO] Westbury - Bristol Temple Meads
1O98 12:52[FO] Bristol Temple Meads - Brighton
1V96 17:00[FO] Brighton - Cardiff Central
2C96 22:50[FO] Cardiff Central - Bristol Temple Meads (via Bristol Parkway!)
5C96 00:05[SO] Bristol Temple Meads - Westbury