Best to ask a gunsmith for help.
You will need to call Colt
probably not................... The magazines are similar, but the 9mm has a spacer in it on the rear of the magazine to accomodate the shorter 9mm cartridge. New magazines in both calibers are available from Colt on their web site (Coltsmfg.com). Ps: a "clip" is a strip of metal made to hold rounds by their base, (google firearm clip) a magazine is a spring loaded box like receptacle where you put rounds in.
Depending on a detaliled description, it could be from 500-1000
made about 1977Series 70 Lightweight Commander - "CLW" prefix, .30 Luger (7.65mm), .38 Super, 9mm, .45 ACP, 1970-1983
You didn't describe anything about the condition it is in. Does it have the box, papers or any accessories? What finish? How much of the finish is left? Any surface rust, wear, or blemishes? What type of material are the grips made out of? Does it come with a factory letter from Colt? Any engraving? They all affect the value. Without more information the best I can do is give you a price range of 500-2000 for a Colt Mark IV Series 70 in 9mm Luger.
You will have to call Colt to find out.
You must call Colt
100-300 usd or so
No
What do you want to know?
the original colt gold cup 70 series is worth about 1,000 dollars roughly
Colt data at Proofhouse.com