ASA and PSIA Instructor
Join Date: Apr 2000
Thanked 30 Times in 30 Posts
Rep Power: 17
That's a signifigant change to make, your knees look like a fine solution, don't try to change unless you have a compelling reason. With any luck your chainplates may be fine, 30 years or not, just open them up enough so you can verify their condition and that of the knee material, which I would assume is a marine wood. Don't rip out anything that isn't rusted or rotted.
Certified...in several regards...