It looks like the parts manual at MIE isn't up to date for that type latch...at least the picture looks like a simple mechanical open-close without the push button. The whole handle assembly is about $70, I think. Are you just missing the button, or is the internal latching mechanism also compromised?
Thanks for the reply rd_macgregor! I think I just need the button, but, the tractor is new to me, so, I don't know what was there in the 1st place... Here is what it looks like (I removed it from the tractor)...
The only parts manual I could find on the internet didn't show that latch (which my DK45 also has). You may have to go through a dealer, who may have a more up-to-date parts listing.