"Spring tamer" Guide works well on the Vulcans. You should be able to take it down by pushing the back block against the workbench and removing the pin. That's what I do. You can hone the sear a little if you feel capable. Apply a little moly. Then adjust the trigger down til it's real nice. Not too much! You don't want it to bump fire. Test it. You won't get to 4oz but who needs that anyway? Real good trigger if done right. No twang in this baby either. If the spring tamer breaks make a delrin guide. The hinge pin should be fine. That gun looks hardly used. I bought a like new Mk2 Vulcan on GBroker. Bargain price. I was the only bidder.The seller lived in Joisey and wanted to do the transaction outside the unfriendly state. We met at Cabela's on 78 here in PA. Halfway betweenst us. Saved me $40.00 shipping. He brought along a very nice Mossberg 20ga and gave it to me. He and his nice wife were retiring and moving to Fla. A beautiful walnut stocked Deluxe Vulcan went on eBay recently. Went for more than I had bid.
My Stingray has 2 pozidrive screws and 2 phillips. WeirdBTW a Mk3 has a "willy wally" trigger. A spring loaded hinge. Same as a Stingray has. Same parts.I think a Mk3 shares about everything with a Stingray except the breech area and the stock. I don't feel like digging the Vulcan out. Been shooting the Deluxe carbine Stingray .22 lately.