In situations like these, you should just leave it outdated or unpriced as the case may be. To illustrate why, just look at your overpay here. I can almost guarantee that the pickel was offered on the muffs and that the muffs owner didn't go to the pickelhaube owner and say your hat + 10 buds for mine. Without overpay, the price here will be TWO buds higher. Makes an enormous difference on value.

Best left alone until a more straightforward sale comes along.