A lot of people may disagree with this one but using one or two Tek screws or something similar will work great, just send one of those screws through the rubber and into the plastic and it’ll hold well. Just don’t over tighten it or you’ll rip through the plastic you’re screwing into. However I’d only do this if you can’t find a good spot to zip tie it up with.
While it’s definitely not great to have 17 month oil. I think it’s pretty safe to say if nothing feels amiss in how it drives, just get it changed and try to keep it under 12 months ;) While it would be pretty hard to say what, if anything, got damaged. Running old or dirty oil won’t lubricate the internals as well thus creating “more wear”. But I really wouldn’t worry about it considering it was only a couple months after the manufacturer recommended 12 month max interval.