A couple of points.
1. This is an Old English weight, and it went cheap, even though it is rather dull! It belongs to the group I have labelled OE2, all of whose members (comprising bottles and paperweights) have very similar simple canes, similar specific gravity, and a limited colour pallet. They are usually good concentrics, although I have seen a couple of closepacks. I wrote a 14 page illustrated article on classification of OE paperweights in the 2007 PCA Bulletin, and have written shorter ones in various PCC Newsletters. Below is an image of typical items of that group. They were made in the 1850s.
2. I think it very rare to find an intentional spiral or heart shape in an old millefiori weight. Never say never, but I think it is just about always due to slippage of the setup during the pick up. I am 99.99% certain this spiral is accidental. It is impossible to make a concentric paperweight from identical sized circular canes without small gaps that can allow movement when heated (unless it is infinite diameter). So you find slippage in many OE weights (including many Bacchus), in St Louis, and so on. In practice, makers adjust the cane sizes to get a tighter fit - hence the 'rogue' canes in some weights. They are not worker's signatures - they are pragmatic solutions to a real problem.