-Have you tried the stewmac heatstick for removing necks?
-If so, how was it? Did it work and heat/loosen the neck in a reasonable time? Any wood burn? Etc
-Where the larger holes you have to drill a problem at all?
How do you fill the holes?
Do you make small dowels and par them flush with a chisel?
yep! Just fabricate small dowel like plugs out of the same wood that your fingerboard is made out of. Glue them in with the grain oriented the same way as the fingerboard.Cut them flush. Reslot the plugs with a .022” slot. Continue repair
I make side-grain plugs, rather than end grain dowels. More work but a better match. It requires supergluing tiny cubes of the needed wood to a long dowel. Let the glue cure overnight, then round the cube to fit the hole in the fingerboard, and then superglue with accelerator. Leave the plugs proud, and trim flush with a chiseI. I got this method from the Stew-Mac DVD on neck resets.
I just got the Stew Mac heat stick with their soldering iron and used it to pull the neck off of a 1930's Kay "Lyre" guitar. Since it was my first time, I tried to follow the video directions as best I could, but just missed the pocket by a mm or so and ended up in the neck block. It took nearly an hour and quite a bit of warming the heel with a hair dryer, but it eventually came loose with just a tiny amount of tear out. I'll certainly try it again and hope to eventually master the process, but I'm not throwing away my old espresso maker just yet!