According to wikipedia: "The Lancashire Artillery Volunteers were first raised in 1859 as part of the Volunteer Force raised in response to threats of French Invasion.[1] A total of 23 Artillery companieswere raised initially. However, in Manchester, numerous units that would later form the Lancashire Artillery Gunners had existed from as early as 1804, when the Duke of Gloucester inspected the Heaton Artillery Volunteers before they were shipped off to the fronts of the Napoleonic Wars
The style is defineitely Voctrian and there are several for sale, including one which at a quick glance seems almost identical to the 5th Lancahsire Volunteer Artillery, described as 'officers, full dress' and found here: https://www.the-saleroom.com/en-us/auction-catalogues/laidlaw-auctioneers-and-valuers/catalogue-id-srlai10004/lot-2a500189-2467-40e6-af43-a4250003ef87
If you google 'Victorian volunteer sabretache' you'll find a number of examples, including a Pintrist page with at least a dozen. Sorry, I'cvwe no idea of value but not cheap, i shouldn't think. Perhaps the sale at the auction house will help, if they publish their prices realized.