Originally i did think of LAM but i think they are like their randonneur version where they have to slid along the bars to be installed.
On these bars there is a very small amount of the original bar tape left and so LAMs wouldn't of been able to slid off the bars to be removed.
But i can't quite remember so i could be completely wrong about that.

I need to do some more research and found out which sort were commonly used around that time.