Re: stucco over old stucco
Yes but check on the following.
If you choose to use conventional stucco with a bonding agent check the product data sheet on the bonding agent and make sure it states that it is not Re-emulsifiable.
The best bonding agent for your porpouse would be 1 part cement , 1 part sand and water to make a paste like a milk shake dash this on the existing stucco as a bonding agent than apply the scratch coat stucco.
The best repair would be to use a polymer based synthetic stucco base coat over the existing than apply a synthetic finish color as selected.
Also be sure all loose tabby is removed.