I have just completed a rolled & silver soldered smokebox for a 3.5" gauge GWR 'City'. There are a couple of minor 'dimps' in the barrel as a result of bending around a wooden former. I'm not happy with these & wish to fill either with a low melting point soft-solder, or a higher melting point such as 'Comsol'. Has anyone any suggestions as to which I should used, i.e would the lower melting point be ok or would it migrate as a result of the temperature of the smokebox?

Thanks to you both for your thoughts on the matter. I think you're right John, it's probably better to remake rather than attempt to fill the imperfections. I shall have to ensure to take extra care with the brass in its annealed state this time around. I have used Comsol on a boiler before, but the temperature probably would not be anywhere near what you suggest for the smokebox -so thanks for the info on the temperature Clive.