Phil,
I think you're mis-reading a fancy lower-case e as an s. See the capture below. It's a blow up of the logo on your site.
I have a Leon Trotte, Mantes a Paris with a different logo. MIne is in the 1600's serial numbering, which could account for the different logo.
There was a Leon Trotte in Mantes who was the president of the Ensemble Orchestral of Mantes-la-Ville from 1956 until he passed away in 1983. If you speak/read French, the link below shows the info, or in my case, I use Chrome and have it translate the page for me.
http://www.ensembleorchestral.com/spip.php?article5Hopefully the attachments will be view-able, both are captures using windows snip-it, so not very big files.