The Trimax Trailer Wheel Chock and Lock - 12" - 15" Wide Tires can be ordered keyed alike as part # TMX72ZR but this only comes with 2 chocks and there isn't a way to order sets of these keyed alike. So you won't be able to get all of them keyed alike, but you will be able to get 3 pairs which limits you to 3 keys as opposed to 6 like what you'd get with the Wheel Chock # TMX75FR. view full answer...
Roadmaster does not provide a trailer connector with the # RM-2050-1 tow dolly. If you want the brake functional, you'll need to install a 7-way trailer connector like # PK12706.
It does appear that you've found the correct connector, to install your Tekonsha # 90195 P3 brake controller, you'll need the # 3035-P harness..
I've linked to our trailer wiring help article which features wiring diagrams that show how the 7-way would be wired. view full answer...