LPC's Wikipedia mentions he switched to skype in 2008. Listenting to the 2018 album back to back with SPCC, LPC has a southern tinge to his accent that SPCC doesn't really have but their demeanor is basically the same. According to SPCC when he was asked by chat and one or two occasions I can remember some people he calls ask him if he's LPC, he's mentioned that he knows who LPC is and is basically ripping him off.
Whe he plays old archived prank calls, it's not just his own voice but several of his co-workers at the call center also doing calls. So, who knows?
It could have been a tech upgrade, Ihere's a clip from the recently released LPC 19.
Yeah it was allegedly Flamenco.
I've never heard SPCC mention anything about it and haven't heard of it before. Based on the archives, SPCC was on Stream.Me well before Ralph moved over. He'd been doing it for several (lost to time) months before people started archiving him.
This is LPC:

Nothing else is known about him.
Based on LPC 19, I don't think they're the same person. Unless he was using a different recording process. What makes it harder is the constant voice modulation and the fact that SPCC was live and LPC was pre-recorded. No SPCC calls or numbers are featured on LPC albums, but then again anyone whose maintained their underground anonymity for this long has more discipline than narcissism. I dunno, who knows?
EDIT: "For the 30th anniversary of LPC in 2018, he wants to do something “big.” “I think I have a little more time I can get away with it."
https://www.rollingstone.com/music/music-news/americas-underground-prank-call-king-speaks-196561/