I got an email back from the tech guy round here, this is what he said:
"70s guitars were normally finished in polyester lacquer which was generally applied thicker than the old cellulose lacquer and is also harder. Polyester has a habit of cracking along joints and forming a few long splits over large areas (instead of 'crazing' like cellulose).
If it is polyester, a fall is likely to crack the lacquer due to sudden but slight movement or vibration of the wood because the lacquer doesn't give to accommodate this movement. It doesn't necessarily mean the wood has actually split, but I would need to see the guitar to check if this is so.
Please let me know if you would like to bring it to the workshop for a check and I will advise you what's needed; whether its just a lacquer repair or anything else. It is possible that the tech you spoke with is correct about inserting glue. I can only give you a price on seeing the guitar, but it sounds as if it's likely to be under £50."
Sound about right? I think I might take it up to him in the week if the price and what he's said seem good :)
