In times of Engineer shortages like these you will find there are a few companies giving conversion courses for experienced qualified non aviation craftsmen (like motor mechanics). I have come across these courses and they take from 1 to 3 months depending on the organisation. In theory the training from an aviation apprenticeship is more thorough and will prepare an individual better for a career as an Aircraft Engineer. But I have seen a lot of excellent guys come from industry which have turned out to be excellent Aircraft Engineers. I think the enthusiasm of the individual goes a long way towards making up for a lot of the shoddy training programs around (and I mean both ab-initio and conversion training!!). So my advice is if you're really interested write to every airline you can, and the third part maintenance companies too. Put up with a short training bond and bad conditions for a while until you get the experience under your belt. Alternatively, finish your commercial license and get a job as a pilot for more money on regulated hours and save a fortune on manicures!!