That connector unscrews (threaded area is where the knurled place & the smooth place meet)....& there are screws inside to connect your wires to.
This is the best buy I've found lately for needles for needles that will fit your machine
http://www.ebay.com/itm/16-vtg-Sewin...item23325afd19 They're size 1...pretty close to a modern size 14. I've bought these and some for a long shuttle National from this seller. The needles were good...& they were shipped quickly