I've been there and done that. First I was pleased with the outcome. Second, if you pay a fair fee for the engraving you probably will lose money if you have to sell it.
Someone with more passion than brains HAS to fall in love with your shotgun and specific engraving pattern and be willing to pay top dollar to get it Now. That is a very narrow market.
Next the engraver has to have the knowledge and skill to anneal then re heat treat the receiver after finishing - or know whom to send it to.
Third, unless you personally know how to strip your receiver and send just the receiver, you will have extra $$$ invested, along with the anneal/heat treat process...
If not a coin finish for English scroll or Bulino style game scene, you will also have to pay for re-bluing your shotgun..
If $$ is not an issue - ignore everything I said but do look at several samples of your selected engraver - and don't assume he can do 'everything'.. Fabbri and Perazzi for example have a suite of engravers that do Scroll and Rose and Scroll - others do deep chisel and others still do Bulino style game scene. A FEW like Fracasi, Pedretti, Brown, etc can do them all but bring your Jumbo CD and get in line for 2020.
Regards,
Bill