Do not clear. It looks unnatural, and ruins any further attempt to preserve what's there. Like
@49autocycledeluxe said, the paint isn't going to come back, at least on the fenders and guard. Frame might surprise you, however. The beauty of a good cleaning (0000 steel wool and WD40 or OA bath) is that you can always take it down to bare metal later. Once cleaned, the boiled linseed oil ($8-ish at the big box home stores for a quart) looks so good, and is so easy to apply. Please keep us updated.