Hi D-U,
apologies for late reply to your query, I've been "Test"ed by a few sleepless nights lately as I'm sure you know #.

As said above Geoff Sandles' website is always a good start for FoD Pub enquiries; most unusually in this instance can give this direct link to the Feathers' page which includes some old photos to add to Slowhands' notes.
http://www.gloucestershirepubs.co.uk/AllGlosPubsDatabase/RAIGConnection.php?pubid1=1404
This good private website includes some more photos of Lydney and area in general, worth browsing.
http://coghlan.co.uk/Village%20files/lydneycards.html
This great aerial view shows what a big building the Feathers had become by the late 1950s.
http://www.sungreen.co.uk/Lydney-Glos/the_feathers_1959.html

It was equally impressive and presumably a lot of hard work for your 1911 ancestors, as shown by these particulars when offered for auction on Tuesday the 23rd June 1914:

"Fully Licensed and Occupying the Most Important Position in the Town with Extensive Accomodation, Stabling etc.
The High Street hotel consists of a large bar, bar parlour, private sitting room, reading room, billiard room, private dining room, commercial room, coffee room, market room, kit-chen, larder, scullery and wine cellar on the ground floor with a drawing room, ten bedrooms, store room, linen room and closet above. On the second floor is a spacious club room, a masonic room and five more bedrooms. The basement consisted of beer and wine cellars and at the rear was an assembly hall, stabling for twelve horses, harness room, a storeroom formerly used as a brewhouse, four piggeries and a barn."

The above details, and a great many more albeit no mention of your ancestors, are from the excellent "Pubs of the Royal Forest of Dean" by Heather Hurley published 2004. The book states Lydney's "principal inn" was previously owned by the Bathurst family, as was much of the town and area since the early C18th. It was known as the Hand of Feathers in 1681, the Plume of Feathers in the late C18th, the Lydney Inn in 1839, then the Feathers until demolished in 1999. An indication of it's importance to Lydney is highlighted within this highly-detailed Kelly's Directory entry of 1861, see http://www.genuki.org.uk/big/eng/GLS/Lydney/Kelly1861.html

Heather's book includes this photo of mounted Police stationed at The Feathers during the 1926 General Strike, are they pictured in front of the Feathers ?
http://news.bbc.co.uk/media/images/46880000/jpg/_46880039_mountedpolice,minersstrike,fo...
Here's some more http://www.gloucestershirepolicemuseum.co.uk/page_2360487.html
175 extra police were drafted into the Forest during the strike, to ensure order after 3/4 of the miners walked out. According to Hylton O.A. Myles of Bream, for example,
"In this village two private owners carried on mining one called "Friars Level" and the other by the late Mr Thomas Peglar at Clements End Green, although only a handful of men worked at these collieries and did not take part in the stoppage. To enable these men to go to work the Mounted Police were brought from Cheltenham to escort them daily to and from their place of work. A few words were shouted with the usual "Forest Humour" but never the intimidation that we witnessed on Television during the 1984 Miners strike."

# oops another poor "shot" from one of our "batsmen", ah well we always let you win the Gabba test, our time will(may?) come.. Not forgetting Cap'n Cook is Gloster-born and you've seen what he can do Down Under.