[Randall-in-Mpls]

Before you make it a bobber, make it a runner. You don't want to put a lot of dollars and effort into a project that can't be finished, so concentrate on the functional issues first.
And once you get to know the bike, your vision might change, resulting in a machine you'll enjoy even more.

 

[Randall-in-Mpls]

It depends on how much you value convenience.

 

[Randall-in-Mpls]

His set had 3 rubber "O" rings, don't know if they need changed every time or not but if they do that would add to the cost also.

Some filters come with both o-rings.
I usually reuse them, so I've been accumulating spares.

 

[Randall-in-Mpls]

Besides, I remember being taught that step #1 of an oil change is driving to the store for the supplies so that the engine is fully warmed up and the old oil will drain better.

If you find yourself needing to make a mid-winter oil change (and you don't have the 3-wheeled option for a warm-up ride) a halogen work lamp directed at the oil sump for a couple hours is a pretty good substitute.

 

[Randall-in-Mpls]

I've had good results soaking those intakes in ArmorAll.