J.W. Benson were a large retail jewellers in London, and did make their own watches for many years, (until bombed out in WW2), as well as using good English makers, (Rotherhams of Coventry were used, and yours was possibly made by them), and also importing quality movements such as Longines and casing them in the UK. The company existed until 1973 when the name was sold to Garrards.
The 'Field' was their best quality English pocket watch in the range of the 'Ludgate' and the 'Bank', and was so named after a glowing endorsement of it by the then editor of the 'Field' magazine. There's a lot of information in the Oxford Pocket Watches website.
The date of your watch, as well as other information, should be visible from the hallmarks inside the case lid, which appears to be gold, so a clear picture of that area will be most helpful. However, the wording on the top plate does indicate that it was produced before the death of Queen Victoria in 1901.
The movement is known as a 3/4 plate, from the way the top plate is recessed to accommodate the balance, giving a slimmer movement. The escapement is an English lever with a cut compensated balance. It looks to be in reasonable condition although in need of a clean. If you don't know when it was last serviced it's not a good idea to run it too much until that's done, because old congealed oil and dirt can be an effective grinding paste and can damage pivots.
As Graham says the Field model is the one that is regarded as the top of the range, however, there are a number of variants of different quality I attach a photograph of a high quality example for comparison. It was also made in Coventry, but by the Errington factory in 1898 - by then under the ownership of Williamson.
Production commenced c1890 and the early examples often have "Queen & Prince of Wales" warrants. Benson did I believe continue to have the Queen warrant on his watches after her death in 1901 - so you cannot use it as a definite indicator of age.
Yes, you are quite right and I know that is what it says on Oxford Pocket Watches site here, but I thought I had read elsewhere that there was a short period between 1901 and 1905 when some watches had the warrant to the Queen without 'Late' - I have had a quick search with no success, if I find it I will post the link.
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I tracked Benson serial numbers and case dates as they appeared in eBay sales for a couple of years. I amassed a data base of over 1,000 watches. Movements were marked
"HM the Queen" until 1901, then "Late Queen" during and after that year. The only case dated year in which both were used was 1901, which makes sense.
Then in 1912, also making sense, "To H. M. the Queen" and "HM the Queen" appear, apparently referring to Queen Mary. This seems to have stopped around 1922.
Thanks for that. Before they were all rationalised in 1975 to change in January, each assay office changed their date letters in different months; London date letters were changed in May each year so a letter 'f' for 1901 could appear on a case made up to April 1902.