The basic W2230 (Class 20 BO - BO) and W 2231 (Class 08) Diesels had been manufactured by Wrenn, Basildon during Period 3/4 in Blue and Green with both Powered Versions and later Non Powered versions. The later ones were not very popular, and hence many were returned to the factory for conversion. 

The only other BO - BO issued was W.2230RF in BR Railfreight Grey, from 1988 - 1990 with just over 100 issued. This I believe was a great success, however Basildon restricted the production I imagine based on the previous history of the Class 20, and other competitors in the market. Due to this small number please ensure that the inner box shows a correct stamp.

During Period 6, Wrenn, Cheshunt issued Class 08 Railfreight Grey bodies which would fit onto the standard Class 08 Chassis.I believe approximately 20 were issued, it is a shame that more were not made.

I find it hard to understand why Wrenn, Basildon did not take a small risk on the Class 08 Railfreight  BR Grey as I believe it would have been popular amongst both Wrenn and Hornby Dublo Collectors including those running BR layouts.

The picture shows both, the Class 20 Diesel ( in correct Wrenn Basildon issued box) and Class 08 Diesel which would probably be issued in a reproduction copy box.Running numbers are 20 132 for the BO - BO and 08 147 for the Class 08