Is it okay to say Salam Alaikum to my kind mechanic?

Assalamu Alaikum everyone, I live in Melbourne, Australia, and I have this mechanic who's honestly one of the kindest people I've met. He always takes time to explain things properly and genuinely seems to care. It really warms my heart. I noticed he has some Arabic calligraphy in his office, so I'm guessing he's Muslim. I'd love to greet him with Salam Alaikum, but I'm worried it might come across as overstepping or even disrespectful. I spent part of my childhood in the Middle East and am familiar with the greeting, but I mostly used it when others said it first. Also, here in Australia, some folks might react oddly to it, so maybe he avoids it himself. Do you think it's alright for someone like me (I’m white and Jewish, though I don’t think that matters much) to use Salam Alaikum with a Muslim professional I respect? If that’s not a good idea, is there another way I could show appreciation for his background? And when Ramadan comes, would it be fine to ask how it's going, or would that feel intrusive? JazakAllah khair for your thoughts!