Revamping old electrical systems

[kar_the_terrible]

Hi all,
Its getting to be that time of year again, and its good to be back on the forum. Im hoping to restore my bike to really good condition before getting out this season.
So here are some questions:

1) Is there anyway to revamp electrical systems on old 70's UJM's?? I know mikesxs can replace points ignition with hall effect ignition etc etc. Any other tips?

2) Engine rebuild. I know I will need a pro at some point of time to help me out here, but I'd like to save as much on labour as possible, so what stuff can I do by myself (assembly/disassembly)?

3) In case I need to rebore my engine, how do I get new pistons? or do you change the piston rings???

Thanks and happy new year!!!