doing the seals from the inside does produce a very nice seal, and it also shows you how to get them that way from the outside...

once you drop it in from the inside it gives you a different view...

dude prefers to use rocks to drive his nails, but has a hammer.

this old scientific manual has some good info.

http://www.survivorlibrary.com/library/a_handbook_of_laboratory_glass-blowing_1921.pdf

for me the ring or maria does work but i kind of liked...