Well, people tend to divide between a pear (put weight on hips/legs) and apple (put weight on belly), but I'm not sure that's the whole story.
Some years ago (20?) – I noticed a mate, whose a similar build/shape, getting a pot belly, so from then on I tried maintaining a just a bit of tension in the abdomen – not sucking it in, but not letting it bulge out either. I *guess* – must admit I've never asked anyone – that a lot of guys (or women for that matter) just let hang out relaxed, which would accentuation any extra weightiness round the middle.
Fat also gets deposited around the internal organs, so that probably wouldn't help.
Re situps – can be bad at just causing the more external muscles to bulge. Probably more use is crunches (upper abs), plank/prone (middle abs) – the latter you're trying to pull your belly button back to your spine using the deeper muscles. Check out Pilates too, that's mostly core stability work (I've been doing that for about 7 years or so)
>I look like an extra from LOTR
I had the little scrotes at the stations near work referring to me as 'Gimli' – didn't know whether to laugh or give 'em an earful. Tho' I do look like a metal band's roadie, being a bit of a metalhead 😉
Stats – 40chest, 76kg, 31-33" waist (depends on how much or little cycling), 5'10, I'm 46)