damaged master cylinder- fixable?

[jeopardy98]

I bought a really nice front master cylinder and lever off of ebay for my 86 250r and when it got here it looked perfect except that the site glass had disintegrated completely from age. The rest of it is wonderful. Is there a way to fix this? Can I cut a piece of thin plexiglass or lexan and use some rtv or similar and fit a new one in the hole or is the whole thing toast? i just wanted to see if anyone has had this happen and how you solved it. If I have to replace it I will end up contacting the ebay seller but if I can make it work I will just go that route. Thanks in advance.

http://i49.photobucket.com/albums/f274/jeopardy98/1986%20atc250r/4acb52b4.jpg

[TeamGeek6]

JB weld a piece of glass in. Ive done that to carbs for a fuel level view window. Bake the JB at 120F to harden it else itll be soft and come apart. It turns into concrete when baked...

[jeopardy98]

Okay cool, I really didn't want to scrap a really good master cylinder because of this. Do I just get a glass shop to cut me a small piece to fit? I imagine I can just take a propane torch to the JB Weld, right?

[oldskool83]

I'd just alum weld the hole shut, check it everyone once in a while to make sure its now low.