worker status and earnings factor 30 years ago…

Hi, I am preparing for a case - HRT refusal - where one of the argument is a child of a worker. We at last managed to get the DWP to provide the appellants late father’s history of economic activities - that dates go back to early 80s. Due to the length of time It only gives earnings figures and no start and end date of employment which triggers the DWP saying that worker status cannot be accepted. The appellant does not remember details of his dad’s work as he was a child and they were estranged.No other relative who can provide this info.
Looking at the NMW from a decade later - his earnings look quite good but is there any guidance that can be relied on with these arguments? Sorry if I ramble. Very late submission ...

If there are earnings every year, or there is a solid run of five years with earnings every year, and the earnings seem reasonable adjusted for inflation, it ought to be possible to infer that he was either constantly in work, or in and out of work without ever ceasing to be actively engaged in the labour market, thereby retaining worker status during each short period of unemployment.  On balance of probabilities, that is more likely than him having one fantastic week every year and then putting his feet up the rest of the time - it should be possible to draw plausible conclusions from the earnings history.

Where there might be a problem is if the most recent solid run of five years with significant earnings ended before 30 April 2004 (two years before Directive 2004/38/EC was transposed into UK law) - see the Diaz case.  But if you can point to five consecutive years with a fair amount of earnings ending no earlier than 30/4/04, I’d say the evidence is quite persuasive.