Okay, now that isn't what I was expecting, and there is now no point in posting the pic of mine....
I'll throw this in as a thought. the Mech side of a Yam 703 will work any (push throttle!) engine you care to connect it to. I'm using mine to control a Merc, and had it working a Suz a while ago.
The main difference is the electric connector. What I did was pull the electrics out the 703 and park them in a panel on my console. (with a jump wire for the Anti start in gear switch). A "mech only" box isn't going to be tooo expensive, as it doesn't strictly need to be Yam or any other brand if the electrics are now divorced from it.
There are plenty of People with physically broken 703s. Could you sell the one you have to fund a replacement?
Other way of looking at it - a "push- pull swap" will give you intimate knowledge of how it works so you may be at an advantage if it ever decided to throw a wobbler while at sea.
So, assuming you go for the alteration, 2.5 golden rules-
1)as I said before, make sure you have abig sheet of paper or card to lay the bits out on, write notes beside each bit (number them as well) & photograph every bit of the disassembly.
2) chances are at least one of the case screws will be seized solid. Assume your case is going to die & you won't be disappointed
(The screw just above the split in the cable cover is into a particularly fragile spigot - don't ask me how I know....
2.5) Open carefully. The top layer is held in place by the lid!