Your seat tube tubing decal is one that, according to HLloyd (decals supplier) was used from 1953 to 1973.

From HLloydCycles.com catalog, Reynolds tubing decals

The "butted frame tubes" means only that the frame main triangle is 531 butted (the seat tube probably single butted -- no butt at the top if a 27.2 mm seat post fits). It probably means that the rear chain and seat stays are not R531, but doesn't mean that the fork blades are not -- I have a 1972 Raleigh Competition with exactly that seat tube decal, but the fork blades also have the triangular "531 forks" decals. Check your fork blades carefully for (probably shinier) regions near the tops, where such decals would have been before they fell off -- I have at least one other frame exhibiting that state of "patina".

Edit: As @juvela has pointed out, the headbadge is an "anniversary" type, but that was apparently used for several years, mid-to-late-60s through 1970 at least. I have no idea what the anniversary was that this headbadge was supposed to celebrate. Per Wikipedia, Raleigh started business in the mid-1880s, and was taken over by Frank Bowden in 1888 or so, becoming a limited liability corporation in 1889.

Anyway, I wouldn't sweat the tubing issue -- for instance, my aforementioned Raleigh Competition is actually a bit lighter than a same-size International model frame a couple years newer, with R531 frame tubes, forks and stays. I weigh frames stripped down to whatever isn't threaded on, and it seems to me that 3 kg (or just a bit more for frames in the 60-62 cm ctt range that I favor) is kind of the break point in "quality" vs "downmarket" -- of course along with build quality which is usually more obvious. Raleigh itself has a (generally) fairly poor reputation, throughout its product line, than Carlton did, and most of their product line that is valued today came from the Carlton business that they absorbed. You have an example that, from photos provided so far, seems to be quite nice in the build quality department, and it looks like the paint might clean up well too. Enjoy it, and the restoration experience!