front brake master cylinder change

I lowered my bars so now my brake lever won't rotate down, having a hard time finding info on a good replacement. A matching clutch lever set would be ideal. Thanks.

How did you lower the bar?

Should have worded that better...sorry. I put on drag bars. Stock one now hits fork upper.

You can install a mc from almost any Japanese bike with 7/8" bars & single disk brake. some don't have a mirror mount.
New aftermarket are available on eb. search kz440 or 550 master cylinder. or search a small Honda. cb350. or whatever.
KTM & Ducati models came stock w a Brembo mc. new brembo are available. but check the piston bore. 12/12.5/13mm.

Most dual disc bikes of the KZ era used a 5/8" bore front master cylinder. Watch what master you get because many are 14mm or smaller and installing one of those will lead to a more spongy lever feel than the bike had previously.

The EX650 master cylinder has a threaded mirror lug and are readily available on ebay. They are late model so internal corrosion shouldn't be an issue either. I put one of these units on my bike and like it fine.

And don't forget to get new brake lines. Reusing 35 year old brake lines is almost as bad as recycling condoms. Rennsport is a popular line supplier if money is tight. www.rennsportautoparts.com/Default.asp
You can also make lines easily using Earl's components. This is my prefered method.

The 550 Ltd has a single disk front brake.

While we're on the subject, what replacement size master cylinder should I look at for the REAR KZ1000 brake? Keen to get something off a modern bike that I know has a lot of life left it in. Maybe R1 or GSXR etc.

Not keen on rebuilding the oem one. Hasn't failed yet so lets call it preventative modifying