It is most important that you bring some form of ID, like a Passport, Driving License or some proof of where you live, like a household bill,
if you wish to sell something to this shop.

Without ID there will be no purchase.

I get asked quite a lot how much will I pay for second hand jewellery or used watches My reply is that there is no set price.
The price that I am willing to pay first and foremost depends on whether the seller is known to me as a regular customer who has supported my shop in the past with their trade. I feel very strongly that trade is a two way thing. You can not walk into my shop and expect me to pay the same price for your unwanted belongs as I would to one of my loyal customers.
There is a trade price for scrap metal that is only available to VAT registered retail members and not to members of the general public. All such sales are recorded by the bullion dealers and the amount paid out passed on to the inland revenue.
The bullion dealers expect the retailers to have sorted the metals by testing and sorting them into different groups, removed gemstones or any other metals such as springs or base metal components. The bullion dealers are very busy people. They do not want to be bothered with unprepared metals or trifling amounts and this why they will not deal with members of the public. It is therefore unreasonable to expect to sell your goods to my business at trade scrap prices especially if you are not one of loyal customers. I will however give a new customer the full scrap trade value if the amount paid out is spent on an item of stock as part exchange. Otherwise the amount that I am prepared to pay will be a percentage of the trade scrap value price and whether the customer wants immediate payment in cash or is willing to wait while I see what the Bullion dealer is paying out (which can vary from day to day as Gold & Silver are commodities that means that prices rise in times of uncertainly and fall when the share markets are buoyant) The percentage I charge to act as an agent varies according to quantity that the customer is selling.
ie £1000= or more I charge a 10% commission
£500= or more 15% commission
£250= or more 20% commission
Amounts less than this are of no interest to bullion dealers and therefore I will have to buy the items outright myself and keep them till there is enough metal to sell on. Therefore I will pay out less when I buy small amounts of gold & silver.
As for buying old watches there are only certain makes that are of interest to this shop. They have to a high quality name or they have to have a case made either of gold or silver. I am not a watch repairer myself so the seller would have to be prepared to leave the watch with the shop long enough for me to get my watch repair to examine the movement and determine the value . Makes of watch that we are interested in buying are: OMEGA, LONGINES, TISSOT, EBEL, ROLEX, TUDOR, TAG, CARTIER, HAMILTON, WALTHAM, RAYMOND WEIL, SEIKO LASALLE, MAURICE LE QUOIX, GUCCI, BEUCHE GIROD, GIRARD PERREGAUX, GARRARD, BAUME MERCIER, EMERICH MEERSON, PIAGET, ETERNA, IWC, JAEGER LE COULTRE, VACHERON CONSTANTINE, MICHEAL HERBELIN, PATEK PHILIPPE, CERTINA.