Oh dear , no answers , don't you hate that OK , I figured someone would have picked this up.Thank you GS4 very much appreciated
The date for the change of paintwork you are looking for is 8th of March 1998.
I got this information from a terrific book by Ed Tonks. There is 6 books detailing the early history of the NR class titled "NR CLASS an early history" , , I purchased mine many years ago. Please refer to volume 2.pages 29 to 32 and the inside front cover and the rear cover for NR30 details.