Sorry I haven't been home for the last week so I haven't had the CoC rulebook. I will get a starting post up tomorrow at some time. All C.S are accepted accept @nerminater for the following reasons.
Default stats can not be 'cannibalised' to add more points into other skills. For instance your Climb is 30 when the base is 40.
In your gun case you say you have a 'machine gun' Im not sure on what you mean by this. If you are being literal, a machine gun in the 1920's would be something like below.
For stats and ease of use, I would like it if you changed the name of the guns in the cabinet and on your person to these specific models. That way we know how many rounds they hold and how powerful they are.
Instead of '2 pistols 30 rounds each' can you replace with 'A .32 revolver and a .32 automatic with 60 rounds of .32' ( If you meant for this to be two semi automatic handguns just put that you have 2 .38 automatics with 60 rounds of .32 )
Instead of ' 1 shot gun 15 rounds ' replace with '12 Gauge double barrel shotgun with 15 12 gauge shells'
And finally instead of '2 SMG's 60 rounds each' replace with '2 Thompson submachine guns with 100 rounds of .45 ammunition'
For the police revolver, replace with a '.38 revolver with 12 rounds of .38 ammunition.'
Hope this isn't to much, Call of Cthulhu can be complicated sometimes, especially in a forum based game.