Welcome to the best car owners forum on the Internet.
DO expect to spend some more money, it's par for the course for owning such a great vehicle. Odds are something, somewhere will need attending too.
Omega's and especially the Elite are packed with things that could possibly play up sooner or later...it's a joy to suss them out, seek advice and heck...even fix them yourself.
I've personally done more DIY on my Elite these past 2 years than I have ever on all my previous cars and 30 years previous.
As stated, check for oil leaks...when the engines cold, run your fingers around the top of the engine, JUST under the cam covers. You'll be VERY lucky NOT
to have oil on your fingers BUT not the end of the world...cam gaskets will need changing.
As long as she sounds and drives happy then you should be ok BUT most importantly, on this forum..read, read read and read again !
EVERYTHING "Omega" is covered here somewhere...the advice priceless.