I've got 3 spacers for this – does anyone know how I should put them on?

The frame is a merlin malt 1.

Also, one side screws in nicely, I can hand-tighten it almost to the end then finish it with the tool. The other needs the tool almost right from the start. Is this a problem?

Thanks!

Check the park tool site but I just took 3 off a malt 2 2009 frame. 1 driveside 2 otherwise I think it was but check park site to be sure and measure the bb shell of the frame

Measure the shell width.

68mm wide shell – 1 non drive side, 2 drive side.
73mm wide shell – 1 drive side only.

The 'extra' 1 is there for mounting chain devices of those bb mounted front mechs.

If it's rough, I'd be very tempted to get a tap run through there at a shop.

if you cant screw it in at least four full turns easily by hand then its worth getting a lbs to sort it out. not a difficult or expensive job and well worth doing.

Thanks all, will take it to the LBS for a look.