Balder, (Edited: While I was composing this masterpiece you have already discovered my observation. I must really try to be more speedy)
Actually, on my Type III example the spring does protrude a wee bit, but from the slightly elevated angle I took the picture it isn't visible.
Your photography is quite good. Unless my eyes deceive me, I do detect the end of the spring that has been finished flush with the frame, and the expected hole is present, just cleverly disguised.