Maritime Mack

We arrive at Heathrow on Aug 30th late morning and would like to visit the Frameless exhibit before traveling to Southhampton later that day. We need a place to store luggage until we are done with the exhibit and Luggage Hero has worked for us in the past but we are trying to find the one closest to the exhibit. The cruise goes to Ireland and Scotland and Wales,before returning to Southampton

We are sailing out of Southhampton in August. There are 5 in our group and would like some input on using Luggage Hero in London.We are planning to attend the art exhibit,Frameless, and want to use the one closest to 6 Marble Arch. Also would like to know what is the best way for 5 with luggage to get for the airport to the to the Luggage Hero. Any recommendation on transportation to Southampton from London would be great as we are from the US and this is first time traveling to Great Britain.