Nice model and the perfect match for the BLI heavy weight passenger cars in midcenrury paint.
Kadee #148-50 HO Scale Bulk Pack - 50 pair #148 Whisker Metal Couplers - Medium (9/32") Centerset Shank
The speakers worked out great. They sound fine. The only issue was that I had to extend the cable to reach the 2-pin socket on the motherboard.
See above