With the hints provide I found a link for a bale seal that seems to have has the same logo on it. Description says:It is probably of Dutch origin, the shield with lion rampart a simplified Dutch coat of arms. The 'R' would originally have read 'R&A', for 'Regten en Accynsen', the Dutch customs and excise, and the number 343 was probably a control number. It seems reasonable to assume that this object was used as an official seal for goods exported from Holland to the UK, and is likely to date from c. 1750-1850.
Mine seems to be more modern than the one posted, but definitely seem related.