Hi Wayne. I have been very interested in these blades for some time, but still haven't found the right one for purchase yet. I find it is very difficult to actually judge the age of these especially since they have such a "primitive" look to begin with and are therefore even easier to make them appear old. Obviously they are still being made to this day and many new ones are passed off as old. That being said i couldn't begin to guess as to the age of yours. It is a nice looking one.
It does seem to me that the actual old ones tend not to have very complex pamors patterns, or for that matter, pamor at all.
I believe what you say in your first sentence is most important. You really like it.
I would be interested in hearing more about what you and others believe about these talismanic keris. There appears to be very little VERIFIABLE information.
If you haven't seen this gallery on Alan's website you should check it out:
http://www.kerisattosanaji.com/kerissajen.html