Czech M53 Helmet questions

Hey all. Would anyone know what a Czech M53 helmet is going for these days? I came into possession of two of them that are the same size (1) but are two different dates (1953 and 1954) Nothing seems to be missing on them since the liners are intact and the chin straps are still good. Also on my 1953 helmet under the front forehead there is a number painted in white that looks like a 39 but the 9 looks kind of like a g. Is this some kind of helmet rack number or was it added later on?