It is a Murray part 1001460E701MA and is still available AFAIK NOS from a lot of sites as it is a common wear part on the Murray mowers plus of course all of the other brands made by Murray
Not sure if the MTD equivalent which is still in production would fit although it will not be plug & play
Same story for the cast iron front axle crossmember the front & rear support brackets will also be needed and then the drag links may need to be modified .
Several shops list it as discontinued, NOS at prices from $ 100 to $ 333 ( AUS )
Check the images of 1001460E701MA to be sure we are talking about the same part