The LC uses the edge connector for fan and/or speaker, IIRC. The LCII moved to pin headers, so you'd need to swap other LC II components to get everything connected. The LCIII board moved components around, making the dimensions slightly different, so the fan placement might be different… Not sure on that one. Moving an LCIII board into an older case might prove problematic, based on photos of the boards.
Maybe relying on Cunninham's law might draw in a complete/correct answer here
I have found that a drop of isopropyl alcohol removes hot glue incredibly easily. (The glue even stays in one piece!) When I am desoldering these analog board capacitors, I remove the glue with alcohol first, and they pop right out with minimal effort.