We've been kicking around picking up a 60 Series in recent months to turn into a resto-mod build of sorts but after lots of number crunching and reflection I am happy to report that we've settled on keeping our current 2022 GX460 alongside of the GX550 Overtrail we plan to purchase next fall. I plan to build out the 460 to some degree and run it for years to come instead of throwing $30-40K+ at a tired 40 year old 60 Series that will be less refined, less comfortable and less reliable. Now to start the build planning stage and possibly start amassing parts.
That would be the smart move IMO. I had a FJ55 Iron Pig in the late 70's and 80's. Loved it. When I went to the Toyota Dealer where I ended up getting a 19 GX460 they had an Iron Pig almost identical to mine sitting on the floor. Not for sale.

I checked it from stem to stern and a lot of memories came back. But what hit me the most was how primitive it was compared to vehicles now. In fact it was part of the driving factor that sold me on the 460. A 60 would be cool an 80 was my favorite. But at this point in my life don't think I'd go back even that far. I may end up doing the same as you and likely will in ~4 years or so.