Its a long time since I did any active work on this. You have found in the 1841 census Daniel was living at home which is consistent with Elizabeth Paterson census entry as only her and son James at a different address. Labourer is the only occupation I have for Daniel. Daniel was the common first name in the early family and there are also some spellings as McAnsh which I found very confusing at first till I found two entries which were obviously the same person with one spelt one way and one the other. There is no industry in Clackmannan. There were coal mines around and farms so I'm thinking Daniel just found work where he could. I believe that Elizabeth was a servant at the now demolished Kennet House and so the legend goes got pregnant to a son of the Bruce family and Daniel was paid to take the blame. Unless I can find him and do a DNA test I'll never know.