It may be of interest to some. I have recently had a crank and rods crack tested by Kearsley Airways - http://www.kalair.co.uk/ - I was put onto them by 'Pauly' who posts here. I had a crank and 4 rods crack tested by Magnetic Particle Inspection and was issued a Conformity notice. Obviously this is all to aircraft engineering standards so when I got the crank back with a green tag hanging off it saying 'Serviceable' I was quite happy. The cost? A not insignificant £125 plus the dreaded. This was their minimum charge. I never asked how much stuff you could include in one batch and still be within their limits.
I'm sure there are other places that carry out such services, possibly cheaper, but Stansted is very convenient for me..