I believe Axel Celius used these pre-formed stems on all of his pipes. He was more known for his good briar and freehand "Fantasy" shapes.
He was trained by Poul Rasmussen and was one of the first Danes to send Freehand pipes to the US.
Celius and his pipes never reached the glory of other carvers trained by Rasmussen (Tom Eltang, Former Nielson)....., but he still has a cult following. All of his Fantasy pipes and Chess line had plateau rims. So this one was obviously chopped off at one time. Personally, I prefer the flat top.
That's about all I remember about Svend Axel Celius.