Normally I walk by this type of glass, however at a sale today I picked this up because it appeared to be of superior quality, heavy thick layer of both clear & Ruby, 1 3/4" polished pontil, superior cutting, etc. Size is 7 1/2" height with a 2 1/2" diameter, has wear on bottom. Is there any way to tell Egermann from Biedermeier production? The color looks as if its a deeper red like Biedermeier more so than even earlier Egermann, but I am at a loss as to how to tell them apart. Thanks for any tips/advice.