Molniya-1 is the actual designation. Your "Molniya-1 (011)" is not a designation - it is the construction number (more accurately, Molniya-1-011).
Similar msns are listed on the kupichic.ru page - Molniya-1-012, '1-015, and '1-017. Those particular msn were noted because they indicate engine changes and/or other modifications. These were:
- Molniya-1-011: Westernized model with 350 hp Lycoming TIO-540 HO6 & Bendix King avionics
- Molniya-1-012: Domestic model with 360 hp Vedeneyev M-14P radial and Russian avionics
- Molniya-1-015: Export model with Vedeneyev M-14P (or Μ-14NTK) and Bendix King avionics
- Molniya-1-017: Export modification; liquid-cooled 350 hp Teledyne Continental TSIOL-550 HO6
And, FWIW, [USER=203]@dan_inbox[/USER] has just supplied an image of the Molniya-2. This shows twin 180 hp engines mounted above the wing, each engine with its own 3-bladed pusher prop. Perhaps the Molniya-2 that you described - "Molniya-2 (022)" - with twin 210 hp engines driving a single prop through a combining gearbox - was a later concept?
-- https://www.secretprojects.co.uk/threads/molniya-400.8777/#post-772586
For the Molniya-5, the FPS you mention stands for the Федеральная пограничная служба (Federal'naya pogranichnaya sluzhba) or Federal Border Service. Therefore, presumably, the Molniya-5 was another Molniya-1 derivative - this time optimised for border patrol duties.
You should perhaps also note that the Russian useage of триплан (triplan) does not mean what 'triplane' suggests in English. Rather than a 'triple-decker', it refers to three surfaces - wings, canard, and more conventional tailplane.
