I would go as far as to say get checked out for B12 deficiency. But try Ricks suggestion too. It could help.

B12 is a hobby horse of mine as I have Pernicious Anaemia as well as PD. The first thing my doctor asked me was, did I think there was any possible link to my long term medications. I looked it up and one of the US PD sites has a fact sheet about it. (Sorry I forget which one.)

I am still not properly medicated for it, but when I have a shot the symptoms you describe which have been making walking quite difficult for me go away for a few days. You may not have the same problem as me, but it is worth a try.

The toe curling though is likely dystonia from wearing off/on. I thought all the leg and walking stuff was from the same source, and put it down to dystonia.

If B12 does work, and I have to say I have only had brief respite, then the PD symptoms stand out much clearer, and it is easy to tell which are which.