I have a handbuilt log home from the 70’s that has black tar / mastic chinking (Black Jack?). Logs are a poorly scribed Swedish cope, so the gap is small 1-2”. A mortar chink intrigues me (serious DIY), especially cost savings over synthetic. Logs are very stable, haven’t seen any movement or history marks of settling. Is my gap too small for mortar. And will future buyers be put-off by mortar chinking? Thanks!