I joined in order to get notifications for the blogs that I can't get feeds for, so this is rather important to me.
In order to get RSS feeds, you have to inspect the page source, do a CRTL+F and search 'rss'. If it shows 7 times, there's no feed for that subforum/blog/thread. If it shows 8 or 10 times, there is (obviously the text of the posts can interfere with this count). If it's 8 or 10, you got to each occurrence and find the link for it (format is https://www.rmweb.co.uk/forum/183-irish-railways-group.xml/ or https://www.rmweb.co.uk/blogs/blog/rss/2515-snitzls-main-blog/ for blogs). If that link is not there, you can't just make your own link from the URL of the page, it doesn't work like that (for some reason).
My question is, why the inconsistency? Is it due to the age of the blog/subforum? Or is it something else?
I know it's not due to authorship, as https://www.rmweb.co.uk/blogs/blog/2626-playing-with-150-scale/ has a feed (here: https://www.rmweb.co.uk/blogs/blog/rss/2626-playing-with-150-scale/) but https://www.rmweb.co.uk/blogs/blog/2091-kelvinbank-a-caledonian-railway-project/ doesn't.
My favourite, Snitzl's Main Blog, has a feed though, so I'm quite happy with that