I did the mast foot check on my Streamlined and was quite surprised when noticing a clearly visible crack running all the way down the lower tendon retaining pin. The pin was also bent into a slight banana shape. Will have this replaced, just a matter of time before the pin would snap completely. No fun, especially if you go for longer cruises as I normally do. Suppose there’s an aftermarket for theses spare parts. Another weak part on the Streamlined is the screws that holds the pin which are out of rather soft steel and easy to ruin when undoing.
Yes, a once or twice a year quick check is not a luxury for your safety...
WRT replacement parts, I ordered mine from Murray Marine (5 tendon and 2 pin + screws) as described here http://www.murrays.com/archive/66-67.pdf.
I do have a Chinook base connected to a Streamlined 2 cups + tendon + Euro pin assembly. Neat since +5 years : no wear, no wobbling, no loose parts, no bent pin. By comparison, I broke a North race base assembly where significant wear and wobbling developped between the base and bottom cup after 4 years. The all-plastic-made North race base couldn't be disassembled (and bolts or tendon be inspected) in contrast to Streamlined.
To prevent damaging the woody deck of your hull in case of a tendon/universal failure, it's good to have a mast foot foam pad protection you can insert inbetween. Or use the foam pad boom bra if you use that.