If you want to find an original 24" (hardnose) bar, keep watching e-bay as they will come up with some frequency. You may find it is just a cost effective (i.e. cheap) to buy an entire saw that no one else it too interested in to get a bar. Chain will be no problem, just about anyone can make up a loop and even most Stihl dealers can get a loop of .404 chain with 77 DL.
If you want to update to a sprocket nose bar, customchainsawparts on e-bay has some 24" grey painted bars with McCulloch printed on them for $20-$30. These are not replaceable sprocket nose bars, more like a consumer bar but chances are you won't cut enough wood with the 1-53 to wear one out anyway unless you happen to be a genuine brute and love to endure hardships.
If all else fails, contact me as I have several well used 24" OEM type hardnose bars but Ted thinks my prices are too high...
Mark