Ah there are FREE manuals to be had. And doing searches on the web will just get you MALWARE and SPAMWARE.
OK, go to this link and open the thread for the pinned topic. It's the 2nd most valuable document on the web for your machine.
Mitsubishi
And, Mitsubishi manuals are not like any tractor brands. There are seldom parts manuals and there are engine repair manuals. That's it in a nutshell.
D1600 eh? KE85 engine. Out of all our engine manuals, our highest in the KExx series is KE75. It's related to the KE85, just smaller.
The KE55, KE75, KE85, KE95, KE135 are all related engines.
The D1600 and the ST1600 the same KE85 engine.
I've not dug deep enough, but the KE70 & KE75 engines are used in the ISEKI machines too.
TX1300(F) = KE70
TX1500(F) = KE75
I bet, there is a TX1_00(F) = KE85. The same engine in your D1600.
So, look at the ISEKI UK dealer site here:
Iseki Manuals
The machines with the most KE series engines are the KE130 & KE140. The KE85 has low production numbers.