I believe that whomever printed the original schematic messed up the early & later Model 219/219B descriptions - the "219B" IS the later, striker-fired version pictured at the top (properly labeled "later"); the "219" earlier, hammer-fired version mistakenly labelled "219B", ILO simply "219".
The "219L" (& 220L) was a side-lever (opening lever).
All early versions can use both early & late barrels, because the actions are cocked via the action of the opening lever.
Later versions can use ONLY later barrels, because the later actions are NOT cocked via the opening lever - they are cocked via a cocking stud on the barrel lug of later barrels lifting an internal cocking lever when the barrel is tipped open.
Since early barrels don't have the cocking stud, if one is mounted on a later action, the later actions cannot be recocked w/o a disassembly (barrel removal) & manually lifting (recocking) the internal cocking lever.
(The later action's cocking lever lies almost flush inside the receiver wall, visible & accessable with the barrel removed)