I was searching for the PRODUCING FACTOR so that you can tune the production, but i found a variable that lets you found all industries available in the szenario. But pls be sure when you edit them by yourself, that costfactor1 > 17 or loco.exe will crash.
Im releasing it, because some of you requested it some time ago.
Explaination:
every Industry has a FLAGSPart like this:
<bitmask name="flags" size="4">
<bit name="bit_0">1</bit>
<bit name="bit_E">1</bit>
<bit name="needall">0</bit>
<bit name="canincreaseproduction">1</bit>
<bit name="candecreaseproduction">0</bit>
</bitmask>
when you add to it:
<bit name="bit_10">1</bit>
the industry can be founded by the player.
im releasing 2 compilation of files for you: one for cheaters (all industries LOWEST price) and one for normal players with standard prices.
Just put the dat files in OBJDATA to give the industries the new status

Have Fun