I basically make stuff up as I go along, making it hard to know how much there is left to do in the Scrapyard until it's finished. So, I can't estimate remaining time with any real accuracy. But, it is quite far along in development and wouldn't need much to be technically complete (albeit not fully polished). I would say that the early Patreon version of the Scrapyard is actually pretty fun to explore, even in its current state. As it is intended to be an exploration-focused level, I'd say that's a good sign. After I get the save management and inventory menu fully implemented in the demo, I'll be returning to the scrapyard to finish it up.
When I think of Dark Souls, I mostly think of level design, such as the way shortcuts, side paths, and secrets are implemented. The scrapyard has a lot of that sort of thing going on. Spyro-style checkpoints will likely be placed in central locations linked to multiple shortcuts, similar to Dark Souls bonfires. And, the companion's health will be changed to drain 1 health point (not max health) per death. The original intent was for this to be a max health change, with Nytro leaving a spark of life similar to Dark Souls' bloodstains on death. But, I ultimately decided to not go quite that far for the base difficulty and instead limit the penalty to simply loosing a single point of non-max health. Although, I may implement the original idea as a difficulty setting later in development.