Sadly, I haven't read Orson Welles' cut of the Henry IV plays. I did perform in a 1996 production entitled Henry IV: The History Plays, which, I have no doubt, borrowed heavily on previous sources, including Welles. Clearly, you lose something in the cutting, but there are benefits to putting the two together. The role of Northumberland, for example, is certainly enhanced by putting the two parts together―we see both the run up to his son's death and the aftermath.
I read Randall's post regarding Thomas of Woodstock with interest, since I am currently playing Mowbray in Richard II, which would make me "Sir Not Appearing in This Play" in Woodstock. Odd to think that if Shakespeare had actually had a hand in Woodstock, the movers and shakers in the first act of Richard II, Bolingbrook and Mowbray, would be absent. Looking forward to hearing from you all. You'll have to excuse me if, new to your group, I lurk for a while. I doubt that, with two jobs for the summer, I will be as prolific as Randall.
Also, check out my theater company: Shakespeare and Company
Book Note: Hag-Seed
20 hours ago