Who are M and Jason?

Really disappointing response so far. Go on. Repost and let's find them.

WHO ARE M AND JASON? Close members of the family will know that I act as "buying agent" to satisfy the Old Man's penchant for second hand books. I recent acquired a copy of "Georgiana" for him. This was the book he was reading at the time Mum died and he wished to replace the copy recycled when we cleared the house. This replacement copy, despite being second hand, appears never to have been read. On the fly leaf there is a dedication "to M 199 from Jason XXX". This begs a whole lot of questions. Who is/was M and why did he/she not read the book. Had Jason completely misunderstood him/her. Was M insulted by the implication that he/she had reached the grand old age of 199? Or did he/she see no future in a life with someone who couldn't manage to inscribe a gift with the full date? So, WHO ARE M AND JASON? The search starts here! Repost!