Read the file line by line. Use regexes to extract parts of text. Use /x to make them readable and commentable.

Also, I used the variable $printed to print a newline before each section except the first one.

#!/usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

my $printed;
while (<>) {
    chomp;
    if (/^&LOG[ ]TEXT:[ ]
         "                # The opening quote.
             [^"]*\\      # Path up to the last backslash.
             ( [^\\"]+ )  # The final part of the path.
         "                # The closing quote.
         $/x
    ) {
        print "\n" if $printed++;
        say "[$1]";
    } elsif (m{^&LOG[ ]Naming_Technique:[ ]
               [^@]+\@    # Anything up to the @.
               \w+/       # Word characters followed by a slash.
               ([^/]+)/   # The part_no.
               ([^/]+)    # the part_rev.
               $}x
    ) {
        say "db_part_no=$1";
        say "db_part_rev=$2";
    }
}
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Save as create-ini.pl, run as

perl create-ini.pl input-file > output-file.ini
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