It is swapable (?) but I'm not sure about an even swap. I think it is...if it is Randall shop-supplied stuff.
As far a wrist thongs go. Some like 'em and some hate em'..."BUT"...(I know...I know) it is a bit of work to drill, install the tubing ferrule and trim/polish etc. I think a charge is not out of line.
Hope this helps, Capt. Chris