Modern Upgrades and Vintage Bikes

So I am new to the comunity and have a few questions regarding how people feel about upgrading bikes.
First off  my bike my choice but the project bike I am working on is my first bike and I Kinda want some feed back.
I have a pretty much stock KZ750E 1983 that the only upgrade I have seen is LED indicators have been changed.
She (cause the bike is a she) has some nice extras that came with it but really my question is should I be trying to upgrade her or should I just go as is 

Think the exhaust is okay its Sebring
Got new steel flex for the brake plus new seals and rubbers
Should I think about suspention or any thing like that.(Koni on the rear dont think they are stock actually)
I will do like electric for usb but any other electric improvements.

Like I want to keep her as stock as possible but upgrades on a nearly fourty year old bike seems kinda smart.

I will not go the cafe racer route. I am kind of a purest but retro mode I have no problem with.

Would love some feed back from all side on this and also any sugestions would be helpfull.

I threw in a few photos

Thanks larry

 

Upgrade all you want, but keep a box of the stock parts. A future buyer may want to bring it back to stock.

Perhaps you should some time perusing the pictures section and reading a few gazillion threads. There is most every kind of KZ imaginable around here, from 650 Ed’s one owner, showroom perfect KZ650, to trikes, to full on drag bikes, to mildly modified and completely bonkers bikes.
Decide what you want the final product to be and how much money, time and money you are willing to spend, and then get after it.

Since you like retro, perhaps some upgrades with period correct parts would be in your lane. 

Gonna be hard to improve upon Koni's at any kind of reasonable price.  You can probably still get alternate springs if the ones on the shocks now don't suit you.

Good Ridin'
slmjim & Z1B3BE

There's nothing wrong with upgrading items if it increases safety or reliability. Better lights, better brakes, better tires all fit that bill. Don't forget a louder horn as well. 

The only limits are your imagination and your budget   Oh and since you are in Germany don't forget the "TUV" 

Definitly will do but I hope I will never sell her.

Yeah the TÜV is a pain.I really appreciate all the advice.

With the right pre-project planning and preliminary discussions with the TÜV ingeneer, you can savea lot of
parts, labour, time, money, trouble and would Increases the chances of success in the technical acceptance test hurdle.
This is the way i go and i never had any problems with my new, youngtimer, classic or oldtimer cars and bikes, exept some minor changes
in the details, like road safety or transgression of any kind of limits.

 
 
 
 

You can never go wrong with wiring reliability upgrades, fork internals, better tires, better brake lines.
Of course, with an old bike even general maintenance items can make the bike feel a million times better.