Silverstone archtop possibly needs a neck reset?

[Bass.swimmer]

Hello everyone! Second post here.

I got a silvertone archtop guitar from my grandma when she died about 7 years ago. When I finally got around to learning how to play, I found it difficult because the action was high, and the frets are pretty worn. Now, I am going to give the guitar to my sister and I want to fix it up nice if I can.

However, I noticed when the guitar was dry (I didn't properly humidify it I'm ashamed to say), there was a slight gap at the back of the heel, big enough to see daylight through. The bridge on it is lowered as far as it can go, but the action was uncomfortably high. However now, the action is ok (1/8 inch on low e, 3/32 on high e). It's pretty humid here with the Midwest summer.

All of this to say, does the neck need reset? On a flat top guitar, it's somewhat obvious when it needs a neck reset. But how does one tell when am archtop guitar needs a neck reset? And if it does need a reset, how does one go about that with an archtop guitar? Does anyone know how the neck is held on?

I have some woodworking skill (I've made a couple guitars, including a harp guitar). I am somewhat competent, but am willing to get it repaired by a professional if the job is very complicated. I know my limits, and I don't want to ruin the guitar if the repair is difficult or if the guitar is valuable.

Any help would be appreciated.

[Bass.swimmer]

Here are some photos

https://photos.app.goo.gl/qGbELTtFmPVKZZfH8

[John Arnold]

This is not uncommon on Silvertones, many of which were made by Harmony. It is a dovetail joint that was not fitted all that well.
Archtops will need a reset when the bridge gets too low. In general, the bridge height on an archtop should be between 3/4" and 1" above the top with playable action.

[printer2]

Here is the joint of the one I did a reset on. Someone started to remove the neck then stopped without doing too much damage and then it ended up with a relative. Just showing a shim I made for it.

[mirwa]

Originally Posted by printer2

Here is the joint of the one I did a reset on. Someone started to remove the neck then stopped without doing too much damage and then it ended up with a relative. Just showing a shim I made for it

Nice fancy shim there fred.

When i do a neck reset, I fit and glue the heel but leave the fretboard extension alone, once the heel glue drys, i test fit brass strips under the extension to get the desired height, then make a shim tapered that goes down about half way

Steve

[mirwa]

Example from a Gibson Hummingbird i did last week.

[MC5C]

Most archtops would have a floating neck extension, not shimmed flat to the top. Anyway, the neck needs to be reset when the bridge can't be adjusted low enough, assuming original bridge and that it could be adjusted right when it was new. Beyond that, old Silvertones are cool and funky (I have one, a Kay) and you really need to reverse engineer it to know what the string height over the top should be. I look for around an 1", or a little more, on a new guitar that I make.

You look at it and think about it, and see if the sides at the neck are square to the top and back, is the neck block moving, have the back or top plates moved with respect to the neck block, does the top have loose braces or show signs of sinking, is the neck extension resting on the top when it clearly should not be. It's a gestalt kind of thing.