I Have a very nice Colt LWT Commander in 9mm  made in 1969 and I would like  to add Low mount Novak sights (milling slide)  beavertail grip safety and extended thumb safety but now I see colt is ready to release one with all that and more I have the sights and other items just have not had the slide milled , just cant make up my mind , kind of hate to molest the 69 model but wont be able to keep both looking for pros and cons from all the knowledgeable folks who know Colts

No lo molesto

Sell the '69, and buy a newer one.  Don't butcher an old Colt.

Paladin

Dont do it.. its almost C&R

All you will be doing is reducing the value (if you care) on a nice old Colt.  Buy one with the stuff already done.

Don't do it!

Why not just get a Colt Wiley Clapp Commander?  It is pretty similar to what you are wanting to do to your LW commander, and a series 70 as well.