Now, there are plenty of unrelated characters from different JAL stories who share the same names (since JAL tends to use common Swedish names for most of his characters), but in this case, I believe that JAL included a few additional hints to tell attentive readers that the Morgan in LTROI and the Morgan in VV are actually the same person and not just namesakes.
Appearance
The closest we get to a physical description of LTROI-Morgan is his caricature portrait in the Chinese restaurant, described in the "Friday October 23" chapter:
Elsewhere in the book it's mentioned that he owns a pair of old cowboy boots (Thursday November 5) and a leather vest (Monday November 9).Morgan has, because of his style, loaned traits from the late Elvis. Long sideburns and a "Hunka-hunka-looove, baby" expression [not sure about this translation] in his eyes. His head sits on a tiny body holding a guitar and standing in an Elvis pose. Morgan is more fond of that portrait than he wants to admit.
VV-Morgan is described as having a fairly similar style:
VV-Morgan being "in his sixties" in 2001-ish would also fit with the timeline, if we assume that LTROI-Morgan is in his fourties in 1981. Furthermore, it's worth pointing out that VV-Morgan gets a more detailed physical description than any other character in the short story even though he only makes a brief appearance, almost as if JAL wanted to call extra attention to him so readers would recognize him.Joel looked at Morgan, who grimaced and drank the last of his beer and got up. Even though he was in his sixties, he bore a denim jacket over a Hawaiian shirt. His thinned-out hair was slicked back with something that was probably Brylcreem. He picked up a worn cowboy hat hanging on the chair and pressed it down on his head.
"Nah", he said. "Can't deal with this. Hard to celebrate three thousand when one could've had a hundred."
"Come on now", Berra said.
"I've tried, I've tried", Morgan said and pointed at the empty beer glass. "I'm not feeling the proper joy, sorry. See ya."
He went out and disappeared in the direction of the square with his hands in his pockets.
Past
Right after VV-Morgan leaves the pizzeria, Berra says this to Joel:
This is not elaborated on, but it would make sense as a description of someone who lost three of his closest friends (Jocke, Virginia, Lacke) to a supposed serial killer and spontaneous human combustion 20 years earlier."Yeah, yeah", Berra said as a kind of explanation. "Morgan hasn't had it too easy, him either. Cheers, Joel."
Location
Of course, in LTROI, Morgan and the rest of Lacke's gang mainly spend time at the Chinese restaurant and not the pizzeria, but this is tied together in Let the Old Dreams Die:
Based on what's shown in LTROI, the only people Lacke told about his revenge quest before his death were Morgan and Larry. He might have shared his suspicions with Gösta prior to the cat attack incident, and Karlsson might have been informed by one of the others at a later point, but Morgan and Larry were the only ones that Lacke frankly talked to about his vampire-killing intentions following Virginia's demise and before his own. Thus, Morgan and Larry are the likeliest candidates for the "odd folks" Karin talked to, and I think it's therefore safe to say that LTROI-Morgan is indeed a regular at the pizzeria where Joel encountered VV-Morgan.Some of the odd folks Karin had interviewed and who then as now hung out at the Chinese restaurant or the pizzeria, had said that the dead person the police had found in Oskar's neighbouring apartment had been searching for a child, a kid whom he claimed had killed his best friend.
I rest my case.