1. my existing jumpers are of 3.5 inches per each now. I would like to make another set but only 1.5 inches each. will they be too short and will it create any problem for too short?
I'm using the below methods for Q3:
If it's gold plated, try "擦字膠" first. If not that effective, try "沙膠". For both, be patient and rub slowly & lightly.
If it's silver plated, try "抹銀布".