I think the reason you're finding it difficult to get in as an apprentice is because you may be regarded as overqualified for having done the full B1 and B2 courses, moreover I reckon you're a bit old for the apprtenticeship schemes as most companies would rather invest in someone thats young and would last longer in the company, normally in appenticeships and as far as I know the company sponsors you for these courses and normally apprenticeship schemes are meant for fresh school graduates.
So apprenticeship is not the applicable option in your case, you're better off seeking a technician or mechanic post, I'm sure you'll be coming across many companies seeking out technicians especially avionics.
Oh and I would like to recommend you not to mention the B1/B2 courses that you had done in your CV such that the companies in which you may apply never misinterpret your application as an engineer post application.
Keep looking.
Good luck