Guarder Aluminum Slide for MARUI HI-CAPA 5.1 (STI / Dual Ver) Type74 G&P have answered both these

G&P have answered both these points with their Gas Charging Collapsible Stock Set which also comes with a very ergonomic pistol grip set so you can alter the size of the grips for your comfort

- WA M4 Hammer Lock (WP57)

When it comes to 1-1 replicas

8 x TRAX1 Rail Screws with polymer washers (We may provide extra washers in the package)

UAC Ultra Lightweight Blowback Housing  CNC Aluminum Ultra Lightweight Construction  Prefect fit for UAC Aluminum Loading Nozzle  Suitable for Tokyo Marui Hi-Capa Series Airsoft Gas Blow Black GBB Pistol

Guarder Aluminum Slide for MARUI HI-CAPA 5.1 (STI / Dual Ver) Type74 G&P have answered both theseFULL ALUMINUM DIECAST CONSTRUCTION Design for Gas Blow Back Pistol Tokyo Marui HI CAPA 5. 1 & Custom Dual Stainless Series Replace original ABS Slide Best in conjunction use with high flow blow off valve Please note self installation is required