Was your game compiled to Z-code or glulx?
reform reverse compiles Z-code to I6. mrifk reverse compiles glulx to I6.
In both cases, the I6 will be hard to read and will not closely resemble the auto.inf that your I7 had compiled to.
There’s no way to get from I6 back to I7. Now that we have the source, it would be very hard but not impossible that someone could write something that would take an I6 file the I7 compiler had produced and generate I7 that would output the same I6… but I feel safe in predicting that the I7 so generated would neither structurally resemble the original source nor even resemble anything a human being would have written.