These were all opened at Quinta do Crasto. The one on the left was provided by Miguel Roquette (son of the current owner of Crasto and who's great grandfather and grandfather made all these). This bottle has been in the family possession since it was produced. The other two were from my cellar, bought at auction in the past 8 years. A lot of emails prior to the tasting, discussion during, and follow up converstaion after ensued as there was some research on Miguel's part regarding the 1920 and 1958. So some of this information is new even to some of the other

'ers who were at this dinner.
The one on the left is a very old
NV Roncao Velho tawny Port. (quite tasty I may add)
The middle one from 1920 is a Colheita. At the time we drank this Miguel had never actually seen a bottle of this 1920, but he had the records at the table proving it was authentic. It had an authentic original capsule. The cork didn't come out in one piece and we couldn't read it accurately (the bottle was saved and given to Miguel).
The right one ended up being a Vintage Port with "Crasto 1958" on the cork. Though the label was a recreation and someone erroneously put Colheita on it, the contents and cork were authentic per Miguel. Though, Miguel had never seen a 1958 in person and had never seen this old of a Constantino VP with "Crasto" printed on the cork. He did find records of a small amount of this being made. Most likely this wasn't commercially released but that is speculation as he couldn't find records to prove either way.
As you will notice the bottle for the 1920 Colheita and the 1958 VP are plain smooth glass bottles. There is no raised logo. All of these bottles were pre-Constantino being sold in the 60's.
As the right two bottles are very similar in shape, it was theorized by Miguel that these were released around the same time period, just prior to the sale of the company. One being a Colheita, the other a VP. That would make sense as the VP would have been bottled in 1960 or 1961. The company being sold a few years later.
The left bottle, being a tawny, has the raised letters. You can see the logo wasn't the best of quality.