vintagebicycle

Do the crank arms have any markings on them? Does it have the Sir Raleigh stamping on the face?
Your bike closely resembles what would have been a Robin Hood, or other Raleigh brand bike of that period.
The chainguard certainly looks like a Raleigh or one of their sub brands too, as do the forks.
Compared to a few Robin Hood and Hercules bikes I've got here the only differences I see are the shape of the rear dropouts, with yours looking more like an actual Raleigh than the Robin Hood or other branded models.
Your fenders also look different from what Raleigh used. What year is stamped on the hub?
The color tells me mid 60's to very early 70's. The two tone head tube is also not a normal Raleigh built trait but that's only paint, anything is possible but Royce Union was known for lowest bidder type bikes, two tone paint wasn't likely anything they wanted to pay for.
What is the width of the bottom bracket shell?
Have you had it apart in any way? What is the threading?

Over the many years of dealing with bicycles I've often wondered if there were more than one Royce Union brand, the Royce Union I remember from the 60's and 70's was a low end, Japanese built brand with serious quality issues, yet from time to time I run into bikes that were obviously built in England or Holland which are of good quality.
While I realize the American owned brand had bikes built all over the place, most were from Japan and build cheaply.
I've also collected headbadges for 40 or so years now, I've got many variations of badges, none of which look related that read Royce Union. A few badges list both Union and Royce Union, others are simply Royce Union, but from both Nottingham and Birmingham England.
About four years ago I came across a vintage rod brake bike, it was a ladies model, likely from the 1920's. The headbadge read Royce Union Birmingham, England. The bike was basically identical to a same time period rod brake Gazelle from Holland.
Nothing on it said anything about the US or NY or any north American address of any sort.
I bought a ton of parts from a closed up shop in VT about 9 years ago, among the lot was an assortment of Royce Union parts, some headbadges, and some brochures from the mid 60's. The bikes in those brochures looked nothing like any quality bike and were advertised as being Made in Japan on a 1967 brochure. I bought a lot of parts, which was mostly all English parts from a guy who ran a shop in northern NJ years ago, I was mainly after the Sturmey Archer parts but in the lot was an array of various other parts, a few of which were some chainguards. One style of chainguard, which was in a Royce Union paper sleeve, said made in England on it, the chainguards mounted the same as a Robin Hood but were more ornate, much heavier and sort of wing shaped.
They were marked as being for a 'Royce Union Roadster'. Another box contained chrome plated chainguards that looked just like those used on Robin Hood and Hercules bikes, (frame clamp hockey stick version). Each one had Royce Union painted on it.
I also ran into a pair of his/hers Royce Union bikes a few years ago at a yard sale which were identical to a pair of Raleigh Sprite 27 bikes. Same red as your bike, Royce union decals etc.

I also have run into a few Royce Union three speeds that closely resembled a Raleigh built bike but the headbadge said Made in Japan.
Some headbadges reference 'Since 1904', others do not. This is a detail that I find puzzling, most brands developed a head badge and design and stuck with it.