I've just bought at a knock down price a Merkur 11C (HD with open comb). The retailer said it should be a two piece, but was now a three piece razor, but still functioned perfectly well. When you open the razor to insert the blade, not only does the head come off but also the twist grip at the bottom of the handle comes out. I can see a round spring around the shaft that would appear to spring onto something to keep the grip in the handle, but obviously that something is missing or broken. Can this be fixed?