Southgate was a very highly respected actioner to the London trade and was credited as such in his obituary. In the said obituary, he was likened in importance to Squires who was a contemporary barrel maker of very high standing.
I suspect that since the over-centre ejector was being adopted by many of the London big names, Southgate's name was adopted as a compliment to his standing within the trade.
Perkes may not have been adopted as he had been involved in the fight with Deeley and all the big names probably didn't want to be seen taking sides!
