It is hard to say, he didn't have anyone when he was alive. He would brag that he had muscle from New York and was later proven wrong but it doesn't dismiss that a close and/or connected Montagna family member from the Bonnano's, may have put a contract; although I believe the later not to be the case.
He had guys around him in Montreal. Don't say you don't know that because you do. But obviously he didn't have wide support in the city and also not enough muscle. I'm confident however that when more evidence is made available it will only support his role in the coup even further. I think he had a bigger hand in the hits on [BadWord], Renda and Rizzuto than Desjardins.
As for the contract, do you think the Bonannos are not capable of it or that they don't care?
Of course he had guys around him. If you recall the Arcuri's,Devito, Desjardins,Montagna & others had formed an alliance. The people around him were all Canadians. In police recordings, the Desjardins clan were mocking Montagna about bring his New York guys that never materialized. They referred to him as Mickey Mouse if I recall. From this fact, it is logical to conclude that if his New York muscle were not present when Montagna was alive and warring with the Rizzuto's; why would New York want to get involved after Montagna's death, if they haven't done so before. Furthermore, I have seen no evidence thus far of any Bonnano direct involvement, they may, and I underscore may, have been indirectly. With regards to the second question, I think the Bonnano's would care to continue their business in Montreal but they lack Canadian muscle at the moment to do the job. The Arcuri's are close to the Bonnano's but they went underground when things got tough, their crew got wiped out. The Bonanno's had good relations also with the Cotroni's for several decades. It was the Rizzuto's that came in and upset the cards. They wanted total domination.