Opening of exhibition in Paris one limits to Corot and Degas? (5)

I haven't cracked this one yet — but the brilliant team at Times for the Times have:

first letter (opening) of EXHIBITION + JE (in Paris[,] one) + first and last of (limits to) COROT This one took me awhile. ‘Je’ is French for ‘I’, but of course we have the “Royal one” here or whatever you call it. I also understood to read it as ‘de-gas’, but I had assumed that this meant ‘remove gas from’, as opposed to — ahem — ‘emit gas’.