Looking at your profile it appears you have some bottom time- my answer would be different if you did not.
In and of itself there is nothing wrong or dangerous about the equipment- assuming it's in working order- that is where the problem lays.
The tank appears to be an AL-80 which is likely made of 6351 alloy. Some shops will not fill it-too long a story for here- as long as it passes VIP+ and hydro it should be OK but be aware many shops will not fill old AL-80.
The reg is fine however it is very unlikely you can get it serviced. Dacor parts are getting hard to come by and a lot of service shops will not touch it. This leaves you with 2 choices- dive it until you don't trust it or scrounge parts and service it yourself. At a minimum I would disassemble, clean and lube it, then give it a full checkup- it's likely it will be OK. This is your call, just make it with care.
The BC may or may not be worth using. I don't know about that model but horse collars of that same vintage (had same LP inflator and vents) had horrible quality bladders in them. I have yet to find one that was not full of holes and the plastic in the inflators and vents get very brittle. I have a yellow one that looks prefect but has several tubes of Aquaseal plugging up the holes and cracks in it. I will wear it as a show piece were I really don't need a BC but never on a "real dive". I also have a blue one that looked brand new but was a total loss inside. Blow it up and see if it holds air, if it does great. If it leaks down slowly over several hours, find the leaks and fix them. If it leaks down quickly, find the leaks and if they are fixable repair them, otherwise make a decoration out of it.
VIPed and hydroded, the tank is fine, the other items are iffy. I dive a lot of vintage stuff so I am not afraid to dive gear in good condition, my double hoses have been to 100ft+ on several occasions and I dive them often. Bottom line on your equipment, as long as it is currently in working order, you are comfortable with the possible failures and dive it in reasonable conditions, I would dive it. But only on simple, well know sites....20-30 in the quarry but it would not go off shore with me.