Popped by here to talk, even though this hasn't had a post in long.
I have a heads-up for Jackster, who's been away for quite so long since last doing any maps and being here, so...
A contributor from The Spriters Resource(if any heard of it yet or not, or haven't seen it in a while), a site that contributes to archiving sprites of all kinds, custom included, has already saved Jackster the work of doing Nazo no Murasam... eh... Actually, The Mysterious Murasame Castle's(the name translated from Japanese to English) maps and uploaded them there, listed underneath a category as "Backgrounds" in the site's NES section, alongside the game's bosses and other misc. sprites, too.
I took a quick stop-in one day, and saw them and the contributor's work responsible for it, MisterMike. I was a little surprised that guy did most of the game's sprites and all of the maps for each stage, and nobody told the VGMaps community about that, nor uploaded its maps, too.
Jackster's mapping plans did include that game, but MisterMike saved that work for him without knowing.
I only found it, so you know.
From looking at them, the FDS game's maps aren't that too large nor complex, but that doesn't mean it didn't present great challenge in its time. Big shame it never got worldwide availability, but, given the FDS' unfortunate problem pileups about the hardware and its splintered reliability, it is kinda understandable. Up until lately, the game finally got that availability onto the 3DS.
The link about that is here -
https://www.spriters-resource.com/nes/themysteriousmurasamecastlejpn/JonLeung, if you're around, I felt this should be brought up to your attention, and take a look at MisterMike's work. Hope you can get a hold of Jackster and MisterMike, when you have time, that is.