This is an unusual example of an early Bach Trombone Stradivarius model 8  with the variation of model 8ii stamped on the bell.  It is suggested that the model 8ii later became known as just the model 8.  Note that the bell thicker brass gauge marking is 51  versus the standard 45, which was commonly used.

Contact us through the website, if you explain the marking of “33” on the main support.