Right, looking through my Silvergate material, it seems that the stuff I have from my old folder will be OK to slot in to a couple of places. Yes, I can fit the 'new' material from my original megadungeon (henceforward, prefaced Mx, to distinguish it as a 'Megadungeon' level, rather than the original Silvergate material) into levels 1 and 1a with a little re-jigging, which will include adding more connections between M1 and M1a, as well as some connections towards Silvergate proper. Because there's an east-facing M1 entrance, and a north-facing M1a entrance (I've worked out what the cave in the 'back of cave' note was - I included it on one of my side-views), these are now going to be in the north-east of Levels 1 and 1a. Luckily, I used the same numbering technique for my two megadungeons 20-odd years apart (originally, I thought the megadungeon material was from around 1987, but I've re-dated it now I've had a really good look at it, and think it's probably from early 1990s rather than mid-late '80s - probably the '1992' I reported the other day is more or less accurate).
I do have some random Goblins and Orcs hanging about about on Levels M1 & M1a that don't necessarily 'belong' but I think I can live with that, especially if I can move other stuff around so other Orcs and Goblins (are there any Goblins? I can't remember any) are tending towards the north-eastern part of Silvergate. The 30+ Orcs I have detailed for the inhabitants of this area can become the main part of the (small) Orc-lair I had marked down for the 'Stirge Caves' area of Silvergate. Guess what's going to be living in the '(back of) cave'?
Level M2 I think still works and maybe can be peopled from the lairs for Silvergate I've already generated but haven't mapped. The old Level M4 map will perhaps have to be scrapped (it seems to be a composite of other maps from published sources) and I know all the usable 'Black Bone Orcs' material (which is mid-'80s, without a doubt) will be put on Level 4 - definitely not the Orcs' map, though, as it will need extensively reworking to make it usable and I think it's probably easier to start again. I will, as an exercise, try to fit the Black Bone material with the existing Level M4 map, and if I'm happy I might leave it. Otherwise, both maps will go and I'll start with a blank canvas.
I have a little puzzle that has occurred due to abandoning this material and then forgetting about it. I refer a couple of times to 'Tholinn' and his (? probably his) hammer in the megadungeon notes. I don't now know who 'Tholinn' is meant to be. Presumably, at the time I was writing, Tholinn was a figure that didn't need an explanation. Some Dwarven ancestor, hero or god, I assume from context, but I don't know which. It's easy enough to pick one - chances are I'll make him the founder and first King of Silvergate, but it would be nice if I could recapture what my original idea was. If anyone recognises the name as a Dwarf deriving from another source, please do let me know! It may well help elucidate what I had in mind when I wrote it.
And then, and then, and then... will I actually get to run it? I've been toying with the idea of trying to find somewhere that will host an open gaming table. If I can, I might try out the upper levels on anyone who wants to try their luck.