Matsumoto I was really looking forward to his letter, but I suppose I do understand why he didn’t want to read it. They’ve known each other for almost 45 years according to Matsumoto, so a serious letter like that is probably very personal
In any case, here’s again summaries of each letter:
Endo told how Cocorico had long ago been troubled most of all by the lack of any special characteristics. This prompted him to seek advice from Hamada, who had then arranged them to have a personal meeting. Hamada’s advice was that Endo could just "follow" him, and Hamada would help him by making it clear to other staff etc. that Endo was his protege. After Endo got divorced and worried that this might soil his reputation, Hamada again offered his council. He told Endo that he should bear all the blame like "a true man", and not attempt to make any excuses in public. Finally Endo asked that Hamada would continue supporting him, and stated that hopefully by Hamada’s 60th birthday he shall have become a bit more reliable and able to support Hamada from time to time.
Yamazaki recalled how 12 years ago he had gotten married, and had held a large and succesful wedding party which Hamada and Matsumoto also participated in. Late that night, when the party had already ended, Yamazaki and his new wife had a big quarrel. They were still going through the wedding presents they had received earlier, and Yamazaki came along Hamada’s present. Since it was from Hamada he thought it would probably be something quite expensive, but instead he found inside a 500 yen kid’s toy coupon. Yamazaki and his wife couldn’t help but to laugh at this surprising discovery, and with their moods improved soon made up. The next day Hamada would also give a more proper wedding present. Yamazaki also declares that people calling Hamada the "big S" surely mean s as in suteki (wonderful), not s in sadistic.
And here’s my take on what little is shown of Matsumoto’s letter:
"To Hamada:
It has been 30 years since the formation of Downtown.
Thinking back on it, this relationship that we now share was not something we were blessed from birth. It was something that grew as the years went on.
During those years long ago, we too had our first time as regulars on a tv show."
Matsumoto jokes that he can only read the letter after Hamada’s death, though he also notes that he might die first. Later he mentions that it might be all right for some staff member to present the letter another time, or that he might read it himself during the end of the year celebration.