Here are the too issues:
- "As I have said this bike is primarily looks" <-- this misses the point of this hobby. You might as well be building a chopper. People who ride adventure bikes aren't doing it strictly for looks (those GS1200s are some of the ugliest bikes out there), neither are touring bike guys, the dirt bike guys, or any other genre of useful motorcycle. Doing it for looks forgoes the riding enjoyment of an improved motorcycle for some other vain reason and that is just cheating everyone involved but yourself most of all. Just because you think doing it for looks is a good reason doesn't mean it actually is one, most of us consider it shameful and a cop out.
- Knee dents. Ah....where to begin....Ok, I don't know how this trend got started but bashing knee dents into a stock tank is about as useless and dumb a mod as you can get. Why? well for starters, most riders can't use them. You aren't' physically making anything narrower, your leg is still limited buy the bottom edge of the tank and the frame rail. When the factories did it on bikes from the mid 1970's onward, the bottom of the tank was always narrower as well. In those bikes from the 1960s that had them, well, those bikes had knee pads and they fell off or the factory neglected to put them on but didn't change the design. How else do they suck? well you can lose up to a gallon of capacity in a tank bashing it in like that. Didn't think about that did ya? on a bike that is a significant amount of fuel, cuts your range down by 1/3 to 1/4. BTW, it doesn't save you any weight because you haven't removed any metal from the tank and usually use a metric shit ton of filler to cover it up. Are there good knee dents? sure, the kinds that ADD capacity to a tank. you don't see them as much because it is 5 times the work and most noobs don't understand there is actually a reason behind some modifications besides looks. If you make your tank hold 5 gallons (the unofficial historical standard size for IOM TT bikes and endurance racers) you are going to need a way of doing it where it won't make the bike wider where the rider sits. But this idea that you can make your bike look "older" just by bashing in the stock tank - that will forever be a poseur mod and one of those things (like clubman bars and stock pegs) that is a clear signal that the builder doesn't understand fast motorcycles.
as far as the filters go - there is a post that may be lost in the tech section now about the different filters and why some suck and others do not and what to look for. The basics are that you want an attachment rubber that does not block or restrict airflow (like a emgo does) but one that has a taper like a velocity stack (like some K&Ns do and like the stock airbox did).
