My Foundation is an '83 and it isn't particularly heavy. Lighter than my G&L and that one isn't particularly heavy.
I thought I could see a shadow in that fret area. I'd give the steaming a shot. I've had really good luck doing that on the back of the neck. Haven't had to do it on the fretboard, but no reason it shouldn't work. Wet cloth, hot iron, do it in short bursts and keep an eye on it.
The steam forces itself into the wood fiber and swells them so the wood starts to fill back in. Have also seen people have a lot of luck with just setting a drop of water into the gouge and letting it set for a time and then hitting it quickly with steam.
I have D'Addario XL170's on my G&L and I really like those too. I also have Ken Smith Burners on my Foundation. The DR's are on the TBC, but I really like their sound.
I would have them on the Foundation, but the only store open only had the Ken Smith Burners. Not a huge disappointment-- it sounds good as well. The D'Addario's might be a good fit, if you don't want to go to the hassle of returning. Try different ones when those die.
Most of all, have fun with that solid old Peavey!