Salam Yaser Sahib,
I have been reading your posts and looking at the pictures of your project. These brought back memories of the time I spent restoring my Triumph Tiger 100. This was a 1970 machine which I tried to restore. At the time I was 25 I didn't know much about how to go about rebuilding engines. I did the work myself, much like you are and after having sunk much money into it I got so fed up with it that I finally just gave it away.
I have categorized restorations in to three categories: Level 1: Retaining 100% or as near as possible the originality of the project. Level 2: Upgrading the project to higher specs or as the Americans call it "customizing" and level 3 - "Kaam Chalao" - Which is what I see has been done to your project.
I am not sure which of the three avenues you wish to persue. I personally prefer number (1) which is the most challenging. However, there are plenty of number (2) and (3) out there.
If you want to pursue method (3) you are doing just fine but putting in Kawasaki pistons and a CB 125 kick start spring etc.
If you have (2) in mind, I can't say anything because that is your personal choice. You could find a complete engine from another (crashed) bike and drop it in. Doesn't mater which one, Kawasaki, Suzuki, Honda or whatever.
If it is number (1) you are after then you need to work with a proper plan of action such as familiarize yourself with the project's nitty gritty. Get on the internet and find out as much about your bike as possible. Plus you need to get the parts book and the work shop manual. You need to make up a list of parts and order them online etc. Using a brazed camshaft is just not acceptable.
In case you want to peruse level (1) restoration check out this link for parts:</SPAN>
http://www.davidsilverspares.co.uk/CL350K3-1971-USA/</SPAN>
Cheers</SPAN>