If you look at Publication 4806 and other IRS information that specifically is for "profit sharing plans", they state the limits but nowhere does it state an increased limit for age.

https://www.irs.gov/pub/irs-pdf/p4806.pdf#page=6

https://www.irs.gov/newsroom/profit-sharing-plans-for-small-employers

https://www.irs.gov/retirement-plans/choosing-a-retirement-plan-profit-sharing-plan

As Susan said, the basic profit-sharing plan is only employer contributions.  There is an add-on feature to have the employee also make contributions (I think that usually makes it a 401k plan).  As your citation pointed out, the participant (employee) can make a catch up contribution.

So back up - does this plan allow participants to contribute, and did the participant actually contribute?