A couple of quick points while I'm passing through:
There is quite a significant database of Cowboy MIDIs at one site on the Web - I don't have the URL to hand, but it should be easy(ish) to find. From memory there are no lyrics posted, but in my opinion the music component is the hardest part of the nut to crack.
I have mused from time to time about creating a site for Australian 'Cowboy' songs. There is no shortage of them available in public archives such as my local State Library. The truth is that I'm an ageing folkie and it's not really my genre, but someone else may be inspired to take up the challenge. Let me know if you need a hand with source materials.
Regards, John firstname.lastname@example.org