The extra "crud" that comes out of my oil usually gets soaked up in newspaper and used to start my furnace. Some people compost it as well.
If I were you, I would not waste my time on hose-in-hose fuel line. Dana sells "how-to" files for making hose-on-hose line. It is much easier, probably cheaper, and works just as well.
The vacuum gauge and temperature gauge are both "add-ons". The vacuum gauge I use is actually a turbo boost gauge, so it shows pressure and vacuum.
http://www.surpluscenter.com/ is a good place to get these gauges. I also have 2 automotive temperature gauges from them as well, but the ones I have are horribly inaccurate. I know there are other good sources for temp gauges around.
As you are working on this project, you should visit
http://biodiesel.infopop.cc/6/ubb.x?a=cfrm&s=447609751 Most of your questions have probably already been answered at some time in the past.