By the way, like you I tried to glean more info from the various old maps. Typical of my luck yet again I found the pub is right on the join between the largest scale maps I looked at, so needed little more effort, however this helped me find exactly which of two neighbouring buildings was the Traveller's Rest. Unfortunately these largest scale maps don't offer any more info than the others.
What is clear that as far as the Ordnance Survey was concerned, the building wasn't considered worthy of a name or description prior to 1900.

Largest scale map, first edition surveyed c1878, just shows the building but no more clues; see extreme bottom left corner.
https://maps.nls.uk/view/109726249

Different (smaller) scale but essentially the same map, first edition also surveyed c1878; see dead centre.
https://maps.nls.uk/view/101453649

---

Here are the next editions of both these series of maps, both revised c1900; now the establishment is given it's current name, and an official key ident, BH for Beerhouse. (The alternative key ident used by the O.S. is PH for Public House. There was no O.S. identifier for "Inn".

Larger scale, second edition, see bottom left corner again;
https://maps.nls.uk/view/109726252

and smaller scale, see dead centre again;
https://maps.nls.uk/view/101453646

----

The first O.S. maps from c1830 wern't such a large scale as the above, hence not so highly detailed and not showing individual buildings, so no more help to us - especially as Stowe Green is once again on the join lines and partially obscured.
eg see extreme top edge of this map, abt middle of left-hand page.
http://www.visionofbritain.org.uk/maps/sheet/first_edition/sheet35

"The hamlet of Stowe had a beerhouse in 1851, (fn. 257) probably the Travellers Rest, which was so called by 1891 (fn. 258) and was still open in 1992."
https://www.british-history.ac.uk/vch/glos/vol5/pp195-231

----

The GlosPubs site doesn't have any history for the pub before 1891, perhaps because that was when it gained the name ?. No direct link possible but it's page is easily found by searching for "Stowe Green".
http://www.gloucestershirepubs.co.uk/AllGlosPubsDatabase/AllGlosPubs_view.php

----

Heather Hurley's book "Pubs of the RFoD" states that "it opened as a beerhouse around 1850 to cater for the lime burners, quarrymen and farm labourers working in the neighbourhood". In other words, no mention of any "traveller's", or it being an Inn ie offering accommodation for them to "rest" in. The earliest "beer retailer" mentioned in the book is Charles Knight in 1879.

----

By the way a "beerhouse" differed from a "public house" insofar it was only permitted to sell beer, but not spirits as well. In theory neither are "inns", which also offer accommodation. Beerhouses were an attempt by the government to encourage working-class people to return to drinking beer or cider as a norm, and not gin.
http://www.historyhouse.co.uk/articles/beerhouse.html

The Clearwell 1880 map at https://www.british-history.ac.uk/vch/glos/vol5/pp195-231 shows a dot on the crossroads just to the right of the name 'Stowe'. That's the location of the inn. The dotted line is the parish boundary.

Newland. Stowe Green.
Edward Gilbert Head 58 1793 Beer House Keeper and Lime Burner
Elizabeth Gilbert Wife 60 1791

This is the only record of a beer house or similar in the area so assume it's the Travellers rest.

I can find an Edward and Eliz Gilbert in 1841 census but he is listed as a farmer living in St Briavels. Could be the same. The location of the Travellers Rest is right on the parish boundary between Newland and St Briavels.

What's the earliest records you have?

Thank you!

Thank you in advance!