Shiboridashi tea pots of this type, without a rim on which to rest the lid, are very difficult to make as the size and evenness of the pot and lid shapes need to match exactly.
Care: do not microwave, do not use in dishwasher, do use diluted soap and hand wash with a soft sponge, dry carefully with a soft cloth.
IMPERFECTIONS - nothing is perfect, especially when handmade. In the Japanese wabi-Sabou aesthetic, imperfections are a form of beauty. It is a representation of the fact a human has made this product. Small spots and other “variations” should be expected.