QEV's are a waste of money and time. I have built them both ways and have never seen an appreciable different. The base on the blue Logic frame was machined so that the LPR sits lower in the frame, not necessary but is saves having to build a spacer to seal the o-ring on the asa and give more room for a good LPR such as the MicroRock.
Laku is correct regarding the set screws that are visible on the blue frame.
The CP direct mount or the CP mini direct mount are the best choice. If Tuna as them that buy it from him. If not I can probably supply one. FYI- I was the person who modified the ones that Tuna has.
The Magnet Mod will definitely give a crisper trigger and use an RT on/off. I have found them to be the best for pneumags. Helps with the trigger/ram return.
......You know you want one!!