Seek and ye shall find in terms of the dash pad wiring length and different handle bars!  https://www.motobrick.com/index.php/topic,570.0.html

Thanks Frankenduck!

Thanks everyone.  I think you have narrowed this down.  When I enter the last 7 digits of the serial number in https://www.realoem.com/bmw/select.do? (6229897) it indicates it is an RT.  See attached pic.  The bike has gone through several owners starting in Maryland, then Saskatchewan, then British Columbia, and now with me in Alberta.  The VIN search and vehicle history reports for Canada and the USA indicate no salvage or accident records.  Thus, I suspect one of the previous owners wanted more of an S model setup and also the after market front fairing or they dropped the bike and the original K75 RT fairing set up was broken and then decided to go with the after market fairing and perhaps changed up the handle bars to the S model setup.  It has a four switch dash pad with ABS, Heated Grips, Hazard warning and an open unused switch port. 

The other thing is that in one of my other posts (introduction one I think) I had asked about the front radiator fairing and mentioned that one of the previous owners had installed a modified fairing with a small aluminum bar strip.  This was done to widened the whole radiator fairing assembly.  Some one mentioned in response that the RT has a larger radiator and thus the need to widen the two fairing halves with the aluminum strip. 

So it looks like I have an RT model that has been modified with an aftermarket front fairing (looks to be a type of Rifle fairing), widened the front radiator fairing assembly, and installed narrower and lower S type handle bars.  Thus, as suggested I will need to find a RT handle bar, and then also extended clutch and brake line hoses.  I do like the RT look and might look at trying to track down a used RT front fairing set up (light section and radiation section).  However, I may just try to update the handle bar and the clutch cable and brake hose lines. 

Well my test drive ended a 1/4 mile from home and I got a good workout.

This time I had my multi-meter with me: 12V at the connector below the tank when cranking, no power at the new fuel pump. Got back, disassembled the float level sender for the second time and the positive connector at the pump was no longer connected to the wire. I started pealing back the insulation to find both wires highly degraded and decided to replace them. But my soldering skills suck and after 2 hours I realized the connection through the fuel level base is also intermittent...gave up and purchased a new fuel level sender. I need this bike running in two weeks and I am starting to get fed up....

Hopefully this cures my problems....

 

Glad you got it all fixed up....
It makes for a nice feeling to know BMW still recognizes that some of these older machines are still operational and need some parts.
Granted it would be nice of all parts where still available, like drive line parts.... but at least we can still get most items. Unlike other brands.
I used to have a 20yr Yamaha and couldn't get much of anything for spare parts.

My meter started working again. I'm not sure what the issue was, but I believe I was 100% able to verify the connections between the coolant temp sensor, ECU, and ground connections. The sensors themselves also appear to work fine, showing ~2200 ohms at ambient temperature.

I dug into the airbox and checked the function of the intake vane/valve thingy and it was moving freely. I did notice a ton of corrosion on the pins in the port on the side of the plenum thing. I gave those a good cleaning before reassembling, and the bike fired up effortlessly! I let the bike idle and warm up for a bit as I still needed to burp the coolant after refilling. It was smoking quite a bit at first, which I assumed was all the gas from my repeated attempts at starting it without air over the last few months, and the smoking mostly went away after a couple minutes. However, after 5 minutes or so the bike started to struggle a bit. I'd give it some throttle and it would pop as the revs came down. Eventually it was stumbling terribly and died. No overheating light and I don't think the fan ever came on. After letting it sit for 20 minutes, I started it again and it ran better, but after a minute or two of warming up it started to succumb to the same conditions.

I took the bike around the block a few times and it was really struggling. I'm not competent enough to say if it was running lean or rich, but it would hesitate to accelerate and felt really underpowered, and wouldn't rev past 5k RPM or so. I'll try starting the bike cold again tomorrow and see if it repeats the same pattern of firing up and running happily before warming up and running like crap.