@BotaDriver
I just ordered a TM1900 and it comes with the B rotor, same as the one you bought. Your experiment last year mounting finish blades on the shackles is quite intriguing.
Now that you have done more 'finish' cutting with your modified mower I am curious if that modification is still working well for you. Do you have any advice for someone considering the same mod?
If you want to do any finish-like cutting what-so-ever, order the blades. After a whole season, roughly 1/3 of the blades needed some sort of attention. Some were in the 'replace' category, others just needed a couple seconds of angle grinder. I did mow over some larger rocks with the unit to see how it would handle them. It's important to know what the unit could handle. I was using it at a family members house and it caught a steel water meter lid. It destroyed the lid (the whole lid, not just a little lift plate in the middle) and didn't do much damage to the blades, and no damage to the mower. I hadn't yet swapped out the blades that needed attention, and I was unable to see anything that looked different than when I last inspected it, which is amazing due to how the steel lid looked (It got pulled up into the unit). I thought for-sure it was a major swap out of blades---still using the factory belts, I did make sure they were tight though.
You can use almost 2x the ground speed with the replacement blades than you can the factory blades, and still get a better cut. You may have to mow regularly every 7 to 10 days, and may still have to double up on any areas that are really thick with grass. The more offset you have the mower, the better (as long as your machine can handle the offset), this is due to the fact that the tires lay the grass down, and since it's a reverse rotation, it doesn't exactly pick it up to cut it. Best results are achieved with DRY grass.
Grease all of its points every mowing (do at least 5 acres per mow)