I have some very bad corrosion on my 455C spring housing. I had the post that holds the carrier roller fall off a few years ago and I had to repair it on site. I plated the other side at home where I had more equipment at hand. I have to remove the bolts now holding the spring housing as the last time I used the 455C the housing let go at the front bolts and was pushed upward by the idler. I should price the housing locally to find out what they cost, but I am pretty sure they are $800 USD plus shipping to Australia is pretty costly.Here is a few pics of my 450C Spring caging housing rebuild. The spring wasn't broken, however the part that caged it was pretty rotted out, of which some repairs, blasting, painting improved things considerable. If yours is just a 450, it may be quite different.