Edward Bulmer's Sang de Boeuf is a gorgeous deep oxblood — that proper ox-blood red the name promises — but Edward Bulmer's natural paint sits at the premium end, and not everyone wants to spend that on a feature wall or a downstairs loo.
The standout alternative is Crown Brick Red, which comes in at ΔE 1.6 from the original (LRV 14.3). Anything under 2.5 is what we'd call very close, so 1.6 is the real deal — once it's up and dry, your eye won't separate the two. Crown is widely stocked through trade merchants and decorator's centres, so it's both cheaper and easier to get hold of.
If you fancy something with a bit of brand personality and a nicer tin on the shelf, COAT Yes Chef lands at ΔE 3.2 (LRV 13.6). That's a touch further off — you might notice a slight difference side by side under strong light — but on its own it reads as the same warm, dark red. COAT's water-based formula is also low-odour and dries quickly, which is handy if you're doing this over a weekend.
Dulux Sicilian Summer 1 (LRV 11) is the budget-friendliest option but the loosest match at ΔE 4.4 — noticeably different in person, leaning a shade deeper and less vibrant. I'd only go there if Dulux availability or price is the deciding factor.
My honest steer: go Crown Brick Red. It's the genuine like-for-like swap and you keep nearly all the character of the Edward Bulmer original for a fraction of the cost.
One practical note — deep reds are notoriously poor coverers. Whatever you choose, prime with a grey or tinted basecoat (Zinsser's tinted to a mid-grey is ideal), and budget for two solid topcoats minimum, sometimes three. Skimp on coats and reds go patchy and blotchy every time.