I bought for the first time an Hungarian Partridge skin. While the feathers seem fine it seems that the tanning process could have been better. The skin smells and there is fat visible in places. Can I do anything to improve the situation such as applying Borax and/or scraping the residual fat off. If so is there a method to it such as how long and in what order. Are there any other ideas? BTW the skin is supposedly no. 1 quality.