That fighting 113 by Jonny Bairstow in Sydney earlier this month made this the third five-match Ashes series in which England had managed just one three-figure score, following 1909 (Jack Sharp 105 at The Oval) and 2013-14 (Ben Stokes 120 in Perth). There was also only one century by the visitors in four matches in 1881-82.
You're right that the Barbadian Dwayne Smith made an unbeaten 105 out of 130 added while he was at the crease for West Indies against South Africa in Cape Town in 2003-04. It was Smith's debut too - and the only century of his eventual ten Tests. By the look of it, the only higher percentage was achieved by Smith's captain from that match, Brian Lara, whose 100 against Australia in Antigua in 1998-99 came while 116 runs were added in total.
There are currently 13 men who have achieved this particular double; the first to get there was Kapil Dev, who finished with 3783 runs and 253 wickets. Arguably the finest set of figures belong to Sanath Jayasuriya, who allied 323 wickets to 13,430 runs; Wasim Akram scored 3717 runs to go with his 502 wickets.
As I suspect you thought, this is a rare feat: only four men have carried their bat for England in a Test down under. The first to do it was the diminutive Surrey batter Bobby Abel, with 132 out of 307 in Sydney in 1891-92. He was followed by Len Hutton in Adelaide in 1950-51, Geoff Boycott in Perth in 1979-80 (when he was marooned on 99 not out), and Alastair Cook in Melbourne in 2017-18.
That brief tenth-wicket stand to save the fourth Ashes Test in Sydney earlier this month had a combined total of 320 Tests between them - 151 for Stuart Broad and 169 for Jimmy Anderson. That's the highest combined total for an unbroken partnership in a Test, beating 315 by Sachin Tendulkar (in his 171st Test) and Rahul Dravid (144th), who were together at the end as India beat Australia in Bengaluru in 2010-11.
Steven Lynch is the editor of the updated edition of Wisden on the Ashes