Partnership share query

It depends on stipulations in firm deed and not stipulated as per Firms Act.  Contact advocate if you are capable of running yourself and can purchase the same as per the market value.  You have remained aloof without participation over 27 years and it is not known about the capital invested by you, your rights, returns from your capital etc.  Do not take this as revenge and proceed only if you have an interest in the take over of the firm  of other partners are disposing to their known persons through underrating assets.