Both Allen and his brother, Frederick Neighbour Simpson, learned the trade of tinsmith, much as their father and grandfather had done, except that they were not apprenticed; Allen learned the craft in the Gawler Place workshop and Fred in the stove factory in Pirie Street.
Both also served in the retail shop where they later took on management tasks — Allen in the internal running of the business and Fred in charge of marketing and purchasing of raw materials: tinned and galvanized sheet metal, rivets and so forth.
A challenge at this time was Federation, and the removal of interstate tariffs, opening up the South Australian market to competition from Victoria.
He traveled without payment to Britain and Europe to learn about the systems of old-age pensions and electric tramways.
He made it clear to his employees that any volunteers for overseas service with the 1st AIF could have their jobs back when they returned.