The formats in a .mpg container are usually cat friendly and will allow you to combine your various scenes into one continuous video:
...and FFmpeg can be used to cut out sections:
cat input1.mpg input2.mpg input3.mpg > combined.mpg
This command will skip the first 43 seconds of the input and then make an output that is 1 minute and 23 seconds in duration. The -ss and -t options can take seconds as a value, as -s is using in the example, or hh:mm:ss.ms as -t is using.
ffmpeg -ss 43 -i input.foo -t 00:01:23.00 -vcodec copy -acodec copy output.foo