Strömbergshyttan B 720 or B920?

Its about the vas to the right. Red underlayer and 220mm height. Maybe a vase launched in 1959-60, and B920? Or a little erlier in mid 1950s, and B720? The sign on a similar vase but little shorter (picture from an auction site) looks like B220, B720 or B920. B220 has not this shape and from 1930s, so excluded. If B720, unfortunately I have no catalog information for that number. But if so, I think it's a Gunnar Nylund design. He used red underlayer in some pieces. But it can also be B920. In that range B919-B924, there are some vases (for example B921) with cutted hexagonal shape. The strange is that no red color underlayer was used in 1960 what I know? And the other model in the first picture (an unknown model number) has the same red color, wich points more to B720 than B920. I think both can be Gunnar Nylund designs in that case. The shorter has precursors in erlier Gerda Strömberg vases with runded cutted sides, and I think Nylund took inspiration from her desin in some models. Also the curved edges in the Marino series by Nylund, was used before by Gerda Strömberg in a bowl on heel. Some models from Strömbergshyttan are very confusing. The design history is not documented as good as for other glassworks. Those of us who are interested try to solve what we can. Unfortunately, I think a lot will still remain unsolved, but we do the best we can.