Looks to me like the primary problem is with the serving temp. English ales (specifically cask ales) are served at cellar temp, which I believe is between 50 and 60 degrees. So at 55 degrees 7 psi will get you 1.53 volumes. That's as low as my chart recommends and sites stouts and porters at...
Increasing pressure does indeed force more CO2 into solution. But you'd better drink the beer in that state. When you pop the top at 68 degrees the excess CO2 will disperse. If you chill the beer down more will go into solution and you will have overly carbonated beer. Here is the force carb...
Got my license in '90 if I remember right...
In order the best I can remember:
1976 Pontiac Grand Prix
1980 Chevy Monza 305ci 4 speed conversion (would smoke one tire as far as you wanted!)
1985 Dodge Charger 2.2L
1977 Chevy Monza Spyder (Still have this one in storage)
1979 Monte Carlo
1976...
I would say to let it sit. I'm going 2 weeks in primary, then 2 weeks in secondary before I back sweeten and pasteurize. Then I will let it sit for another couple of weeks before I start trying it.