Help with separate link tracks!

I’ve just about finished building a trumpeter 1/35 BMP-1 that has separate link tracks, it’s the second time I’ve had a lot with them, the first time was a disaster… does anyone have any tips on this frustrating process!

How do you put them together without them falling apart all the time? They loosely click together, but as soon as there are more than 4 or 5 they fall apart (some are looser than others) - it’s quite annoying…

When / how is best to paint them? It seems that if I build and add them, and prime the model as a whole it’s going to be real hard to paint after… the gap between the top of the tracks and hill is very tight. If I paint them as individual links they won’t glue together, if I manage to fit them together then I imagine painting them before adding them onto the model is best, but will still have issues…

Would love to know if people have. A decent method for this….