Ok simple question. How closely do you have to match the size of the vases? Say I want to get a replacement or just second base for a change of style or just for the fun of it. Do the two have to be the same size or is it just a matter of grommets. IN light of recent Sahara Smoke posts I have been looking at the clearance section thinking I can get the vase of my dreams or very close for less than 5 bucks but it has a 1 3/4 opening where I think mine has a 1 7/8. Would I just need to buy a grommet from them?