as I thought. I think the Spa probably does designate the region which would place your MOP piece in Belgium. There are also advertising pieces that can be viewed on the web mentioning the Belgian location in the late 1800's as having gambling "like Monte Carlo".

To further confuse things, there is a hotel in Italy (Syracuse) that is currently open and uses that name with the word spa as a description of the facility, not a city. No indication that this place in Italy existed in the era which would have produced your MOP jeton or that the hotel offered gambling.

I think Belgium is probably correct. I found only metal tokens shown on the web from that location though. Maybe Benedict could show a scan of a token catalog that does include your piece.