Advice on Emploment

Hello, I am wanting some advice on employment for my 22yr old Son. Diagnosed with High Functioning Autism with complex communication issues.

My son has been working voluntarily for a Heritage Railway for the past 2 years. He has shown a good apptitude in all areas he has been trained in. Including the standardised code and tests for railway safety. He currently volunteers as a train guard as well as other areas of maintenance,  of the safe running of the Heritage railway.

There have been various full and part time jobs advertised which he has applied for over the past 2yrs but not even been offered an interview!! 

Being my sons official appointee, I contacted the company on my sons behalf to ask for an update on how they see my son as a future employee. Mainly due to his Job Coach at the Job Centre asking for an appraisal. 

I received an email from the HR and Manager stating how my son was a valued member of the volunteer team and was often willing to undertake jobs that other volunteers and permanent employees shyed away from. He is safety conscious and has shown vigilance in ensuring all the safety and safe running of the railway.

My son has applied for various permanent jobs that have been advertised, but at the time it was felt that he did not fit the criteria for the job advertised. 

This year the company have expanded and are now advertising for various seasonal, aswell as permanent roles. 

All of which, my son has training and experience in, as a volunteer! He hasn't so much as been offered an interview!! 

I feel the company are now taking the proverbial but my son loves the work and volunteer roles. I'm at a loss as to what to do!! I don't feel I could stop him volunteering as it is valuable work experience and to be fair he loves it so much I don't think he could just walk away, without it destroying his confidence! 

I'm hoping someone can help me out on where next to turn for help!!

Thank you