This was in the April, 2008, Reynolds newsletter, so the news is nearly a year old.

How do you celebrate 110 years of service to an industry ? Reynolds have many ideas that will be announced as the year goes on, but the first one is :-
Reynolds have found a material that is very close to the 531 specification we had in our range for many years. We do not plan to introduce this back into the main range, but from May 2008, there will be a limited supply of tubes to the following sizes, for lug construction, complete with 531 decal.(We hope to have a new retro style, not the one shown)

25.4 x .9/.6/.9 x 600 (ref AB111)
28.6 x .9/.6/.9 x 650 (ref BB123)
28.6 x .9/.6 x 635 (ref CB103)

Please contact us or our distributors for price and delivery information.

Note the phrase "very close to the 531 specification" in the announcement.