Hi Bob, your right! 7 will be half way through it's compression stroke which creates a danger of any ignition leakage from 5.
How solid are you on all boots being the same? The reason I query is that windy city muscle on ebay is selling repro lead sets in which No 7 is a right angle boot.
I have to admit though, a right angle boot doesn't ring right or seemingly offer any advantage.
Also, whilst the AIM is only pictorial, it doesn't indicate any difference with No 7's boot