BSA Springer Tuner

I just bought a BSA Lightning Tactical (UK made) in .22. I’ve only done some initial testing but it has proven to be very accurate and I love the handling. However I have found that the trigger is incredibly heavy and the first stage travel of the trigger doesn’t fully reset. I have tried to adjust the weight by using the trigger weight adjustment screw but found that it makes the gun unsafe (gun can periodically discharge when closing the barrel). 

My question is, does anybody know any good tuners who can do good work with the trigger (while ensuring it is reliably safe) and possibly clean up the internals (polishing, light lubing, etc)?

I’m also curious how much a thorough tune costs, especially considering that BSA springers are supposedly harder to work on than a TX or HW.

Any suggestions or price estimations would be greatly appreciated.