It is the softer and more businesslike / commercial and communication skills which are needed for a H&S career now, and where your development may be better focused. Add a training /presentation qualification to your portfolio, (although beware how you go on to use this) also anything in management, budgeting, marketing, coaching or similar skills. Auditing straddles the technical with the broad-brush, as do systems and project management.
Read widely, watch TED talks, practice using software (word, excel, powerpoint) to be able to produce material which people actually want to look at. Find a way to set out your self-learned knowledge without relying on a qualification as such – so your CV can be sprinkled with words such as 'quality, environment, systems, auditing, presentation' etc.
You can’t fib about qualifications but being knowledgeable about something or having ‘awareness’ is different. My experience is that employers / agencies only ask for primary qualification proof – can’t recall any ever wanting more than Dip, more recent NEBOSH and once, PTTL, as I was going for a training job.
The CV is the key to opening the door to an interview. Work on this, as you obviously have a good background. Will your training fund cover CV help? This might be the best and quickest fix. Make sure your CV shows you in the best light. It's OK to have more than 2 pages if you have done stuff in your life, so dont be swayed by some CV guides - specialist H&S agencies can help here. I had 3 pages but constantly changed the accompanying letter (not always proper letters but the bit that says "what else?" on electronic applications. Have at least one in a Word doc ready to adapt.
Check you have variety in your career listing - if you have been in one company for 20 years split this up into each different role or promotion, reducing content as you go back. In any case, remove references to dates or your age, where possible. There is a way of doing this for your LinkedIn profile too (google). You do have a LI profile don’t you? This gives the opportunity to present yourself slightly differently, but aligned to, your CV - bit more personality. A good, professional photo essential. You will notice that your profile gets checked after each application splurge. That tells you something!
Sell yourself via CV, letter or telephone as an engaging person with a capacity to learn and quickly embed in an organisation. Good luck.