It says that the restaurant is near the station and I know that Shakujii-koen is where Haruka lives so I searched for "Shakujii-Koen Ramen" (石神井公園 ラーメン) on Google Maps and looked on streetview at the results it gave me.
Haruka lives somewhere around Shakujii-Kouen station. I would guess Mariko visits the Soba place first because she wants to get breakfast before getting food for Haruka.
He has taken more breaks recently if you look at the raw page. Four weeks off in 2025 so far but those weeks off also involve doing tankoubon stuff and travelling for reference material.
The are multiple references to Shidenkai in Haruka Reset but I haven't read it yet so I don't know them all. It ended 2 years before Haruka Reset released, though.
That's what came up when I was translating it. Japanese wikipedia said "Purple Highway of Angels" is the official name of the main character's motorcycle gang or something.
Yeah, Chamberlain's translation is very verbose but it's also 140 years old. Wasn't going to do it myself and it is the only public domain Kojiki translation out there.