1 pointInjecting gammon will cure it a lot faster than dry curing. Commecially they do it in a matter of hours using vacuum tumblers however for home curing it is still best left for about a week to 10 days to ensure that the brine is distributed evenly. My last 15 Kg of gammon I left for 10 days, however the current 15 Kg will only get a week as it is needed for Christmas. After smoking, vac pack it and allow it to stand for a couple of days. The smoke flavour will not have fully equilibrated by then but there will be sufficient flavour along with the flavours in the brine. With Gammon, unlike dry cure bacon, you are adding water and so there is no weight loss target. In fact you should get ~5% weight increase due to the injected brine.
1 pointYes Maldon is OK, although it is an expensive option. The type of salt used in the cure makes little difference to the end result as it is there to remove water from the fish and most is lost in the brine produced. I took advice in the early days from Forman & Field and they use, standard fine grain cooking salt - the same as you buy in 1 Kg packs in most supermarkets for ~50p per Kg. Whichever brand you use, it is best if it is fine grain - as this mixes more evenly with the sugar to give a more homogenous cure. If you do use the Maldon and it is in flakes, pulse it in the coffee grinder for a second or two to break them down. You are looking for fine grains and not a fine powder.
1 pointI would leave it until the end of the week then you are good to go. The official shelf life (vac packed at <4 C) is 10 days but it is fine for up to 2 weeks. If you already have the salmon, fillet it and pop it in the freezer until the day before you will cure it. The freezing and thawing actually helps initiate the initial water reduction in the fish.