That is a very clean old buildup. May I suggest that you sit down and polish it out the best you can and then see how you feel.
On a side note, last November I went to a show and one of the old time vendors who had been doing this for years was retiring. This was his last show, he had sold his entire inventory to someone else. So at the end of the day when we started packing up, I went through his stalls of kits, parts, etc. I had been hoarding an old glue bomb Ranchero for years just to try and save the full roof. But low and behold this guy had an unbuilt one in its box. He was feeling very generous and sold it to me for $7.50 (now ducking, lol)
I picked up one of the new Revell Ford Custom kits and hope to use the best parts of it to build a real nice Ranchero.