I suggest you go to your local library and look at a copy of the Writers and Artists Yearbook. This lists all sorts of agencies handling publishing. Don’t bother with literary agents or mainstream publishers, but check out the listings for publishing services. Here you will find reading and evaluation services. They will take a look at your manuscript and decide if it can be made commercial. But beware of vanity operators – getting you to pay to have it published.
I wrote a book about military flying in World War Two – based in part on testimony I had gathered from veterans. 20 literary agents turned it down (and I had a track record in successful books and as a TV producer and scriptwriter). Thankfully Splash TV have put it out. You can read a sample chapter for free at: http://www.ofsonsandskies.com

The value of radar at the time of the B of B has been vastly exaggerated in places. British radio direction finding was very crude and limited at this stage in the war. Wobbly flickers on cathode ray screens, unable to distinguish friend from foe. Mercifully we had good management of vigorous airmen, sufficient to rattle Hitler’s invasion ambitions. But once the Luftwaffe commenced night-time blitz raids, there was no effective means of deterrence.
Robert Arley, Of sons and skies

The touring of a Luftwaffe aircraft around the States at that time was part of a very determined campaign to ‘nudge’ Americans towards being sympathetic to the Brits, and thus inclined to support our war. Focus group research was conducted to evaluate what generated a constructive opinion among US voters. Of course, patently none of this was a patch on the nudge of Pearl Harbor.
Robert Arley
Of sons and skies