Trim Sender for 1998 Osprey / 1999 115 ELPTO

[Motox125]

Hi all,
I'm new to the forum and look forward to the wealth of knowledge here.
I'm deep into several projects on this boat including replacing all of the gauges.
One being the trim gauge.   The motor (1999 115 ELPTO 2 stroke carb, s/n OG77xxxx) does not have a trim sender.   I looked pretty hard through the Merc catalog for this model and s/n but am not seeing it.  Can anyone help confirm the part number for the trim sender?

[fitz73222]

No Trim sender offered, I've never seen one on these in line fours.

[Motox125]

Thank you for the quick answer.  I guess that's one less gauge to replace

[fitz73222]

I did find what appeared to be a universal model that is offered by Mercury. I could not find it in the normal parts schematic so dug a little deeper. 

https://www.ebay.com/itm/Mercury-New-OEM-Trim-Tilt-Sender-Sending-Sensor-Unit-8M0074846-821180A6-/200877565582#rwid

[Motox125]

Thank you for the feedback. 
The motor does appear to have the mounting taps.  See pic.

Maybe there is hope for the universal trim sender unit. 
Although, the one in the link states port side mounting and my taps are on starboard. 
I assume the gauge would read backwards (Up/Down) so I would look for one for starboard mounting.

Also, the pics below show my motor trimmed up and down. 
The resulting motion of the piston shaft pivot screw slot is pretty minimal.   
Is that the typical amount of motion required to change the resistance enough for the gauge to read full up and down?.  I assume the sender is just a potentiometer

Regarding the slot, when I look at the picture of the sender I don't understand how it engages with the slot in the pivot screw.  Maybe I need a different screw that has a specific head shape to interface?