The return roller thang . . .
Using a small screwdriver i began to press the axles out , followed by a good tug .
. . . Phew . Now the easy bit . . .
. . . Remove the outer . . .
. . . and saw off the inner boss .
. . . A 3mm hole was drilled 3.5mm below the old one and using the drill shank as a guide , the bits get glued back on in reverse order .

. . with rollers and tracks back on back in , you can sit back to enjoy the fruit of your labours
a straight line between the idler and last roller , with the sprocket a tad lower , which is how they look in photo's of the real thing .