I have a 1930's house where I've removed the wallpaper and chased out the walls for first fix electrics and plumbing. There are a mixture of surfaces that need plastering, bare brick, sand and cement, matt paint which has been washed down and the original lime plaster. Some of it has fallen off due to all the wall chasing but it mostly appears to be strong. Should I hack all the plaster off and start from the bare brick? Tools I have so far are an sds hammer drill with chisel bits and sds whisk for mixing, a plastic hawk and a set of cheap draper trowels. Am looking to get a decent worn in trowel and a 600mm speedskim ST and SF with pole attachment and a water sprayer. Would this be a wise purchase? Would I need any other tools to get started? What is the best type of plaster to use for a nice matte finish?