Here is the scoop on El Presidente RB:
Cap:
Drill diameter 14mm or 35/64; tube diam 0.539; tube length 1.97; bush 0.621/0.667 (0.510 to fit in tube)
Body:
Drill diameter 31/64; tube diam 0.472; tube length 2.33; bush 0.609/0.550 (0.447 to fit in tube)
Hope this helps. . For the FTN, the tubes are shorter ... all else the same ... can send you lengths if you want.