Short answers, pulled from the story.
Excavations by Sir Mortimer Wheeler and Tessa Wheeler in 1928 uncovered a bronze arm with spoon-shaped fingernails, over 8,000 coins, nearly 300 bracelets, and a dozen dog figurines. The site also yielded oculists' stamps for eye ointment and lead curse tablets dating from the years 301 to 410 AD.
Stone dedications identify Nodens as Mars, the Roman god of war, though he acted as a healer rather than a warrior at Lydney Park. Flavius Blandinus fulfilled a vow to this combined deity, and inscriptions like those on the lead tablet link him to Roman imperial figures during the occupation between 71 and 300 AD.
Scholars reconstruct the name Nodens from Proto-Celtic stems such as Nowdont- or perhaps *snowdo-, linking it to the Welsh noun nudd meaning mist, haze, or fog. John Carey notes no etymology has been accepted with full confidence yet because the sound shift from sn- to n- remains difficult to justify in Gaulish or Proto-Brittonic languages.
Nuada Airgetlám served as the first king of the Tuatha Dé Danann after losing his arm in battle and receiving a silver replacement from the physician Dian Cecht. The Welsh hero Nudd appears in the Triads as one of three most generous men in Wales alongside Rhydderch Hael and Mordaf Hael, while his son Gwyn ap Nudd rules the Welsh Otherworld.
J.R.R. Tolkien visited Lydney Park and traced Nodens to Nuada of the Silver-Hand during his research on mine-shaft holes resembling Hobbit-like dwellings. Scholars note the name Celebrimbor means Silver Hand in Sindarin, echoing the Irish epithet Airgetlám, which likely influenced the creation of the Mines of Moria and the Rings of Power.
H.P. Lovecraft introduced Nodens as an archaic god serving night-gaunts in his 1926 novella The Dream-Quest of Unknown Kadath. He appears again in The Strange High House in the Mist riding a large shell carried by dolphins with Thomas Olney watching, where he opposes Nyarlathotep yet remains somewhat benevolent compared to other cosmic horrors.