Aren't there professionals who restore old wedding dresses and such?
Yes, there are. And I was going to respond to Hair about that when i finally get settled here tonight. You can locate a professional BUT - not just any dry cleaner. I think a lot of them would say they could do it but not really do it. The fabrics get delicate as they age. Certain precautions need to be taken.
One thought is, to have it delicately cleaned and use it aged. A lot of people do that with vintage designs.
The other option for the aged look is that if the fabric is too "yellowed" as opposed to a more appealling off white or beige color you can use a light tea solution to make it beiger instead of yellow. That may not be an option you want but does give a very pleasing outcome.
I would check with restorers first to see if it can be returned to white.
Oh, Hair, also, if older laces are already yellowed, bleach often makes them yellower. Thats when they need bluing. The blue helps remove the yellow cast. But, you have to be careful with that too so that you don't go too far to blue.
How about the linens? - I can photo them if you want, but they dont' feel particularly delicate either, just have yellow spots.