The problem with the perches is not the attachment, it's the sealant. They were hit or miss as to how well they sealed the welds. If you peel it back to check, then you have to reseal, if it's all corroded, you'd have to replace, and there's likely to already be enough degraded metal at that point that you won't have anything to weld to.

That said, if you have some metal and could figure out where to tie on to strengthen it, it's worth a look-see.

Good luck.