I should be able to help with most things but can't help with a swinging arm. The later type can be converted. You need to remove the lugs (big angle grinder!), weld on a plate for the torque arm, weld on a couple of mounts for the chainguard and make some sleeves for the swinging arm spindle. You can use the solid spindle type bushes or you can go for a bronze bush conversion. Been there, done that!