The 74's had the aluminum turn signals (at least my 2 74's do). Also the 74's had the longer front fender with the rear brace. Does the tranny have a kickstarter? The 74's did. (my feeble eyes can't make one out). It must be and end of 74 production run bike if it's not a 75. 75's have the newer handlebar controls, larger diameter front axle, no kickstarter and better tranny, etc. among other things. The shocks as mentioned may be newer but do not have the aluminum 3 ribbed shock covers.
I would want to know some history on the bike. Is he the original owner? How many owners? What's the mileage? Although higher mileage on the bike may not be an issue if properly maintained it can give some indication of rear drive wear, clutch wear, spline wear, etc. How often and when were the splines last lubed? Based on the seller statements that all fluids have recently been changed and lots of other routine maintenance items have been done/replaced/renewed (except perhaps the splines) and the fact that it appears to perhaps have been repainted I personally would be very interested in having some of the above questions answered to my satisfaction. Having all of these services performed "recently" leads me to wonder if they were performed on a regular basis previously. Or if perhaps it sat around for some time. The asking price is not out of line for a /6 in nice mechanical condition, especially with original paint/pinstriping, but I personally would really have to feel comfortable with the answers to these and other questions prior to making an offer of even $2000. Great bikes though.