Paul
Enjoyed your post of The Golf Illustrated article of Rosapenna date 6th May 1910. The course had indeed changed from Old Toms original of 1891. Although I have done very little digging regards Rosepenna, I am aware of the changes and certainly the last 9 which seems to have changed two or three times. This I believe is down to ownership of the land and a couple of other factors. I have also been advised of the following which you may find interesting.
The first OTM 1891 course was around 5,881 yards bogey 83, whilst the 1910 is 5,933 bogey 81. The course compare as follows
OTM 1891-3 Browne/Vardon 1910
1. The Cove -358 yds Bogey 5 1. Avenue 178 yds Bogey 3
2. Muckish 329 yds Bogey 5 2. Rock 410 yds Bogey 5
3. The Target 187 yds Bogey 4 3. Castle 309 yds Bogey 4
4. Tramore 332 yds Bogey 4 4. Mulroy 348 yds Bogey 5
5. Abbey 325 yds Bogey4 5. Coastguard 356 yds Bogey 5
6. Carrigart 400 yds Bogey 5 6. Ganiamore 300 yds Bogey 4
7. The heath 225 yds Bogey 4 7. Magherabeg - 335yds Bogey 5
8. Avenue 225 yds Bogey 4 8. Hays 136 yds Bogey 3
9. Castle 225 yds Bogey 4 9. The Cave 412yds Bogey 5
Out 2,606 yards Bogey 39 Out 2,784 yards Bogey 39
10. The Rock 250 yds Bogey 4 10. Trabeg 375yds Bogey 5
11. Plateau 400 yds Bogey 5 11. Muslack 249yds Bogey 4
12. Ganiamore 350 yds Bogey 5 12. The Cave 358yds Bogey 5
13. Sheep Haven 400 yds Bogey 5 13. Muckish 329yds Bogey 5
14. Royal Hole 400 yds Bogey 5 14. Target 187yds Bogey 4
15. Trabeg 425 yds Bogey 5 15. Tramore 332yds bogey 4
16. The Caves 525 yds Bogey 6 16. Paddys Corner 460yds Bogey 5
17. Lake 225 yds Bogey 4 17. The Hearth 559yds Bogey 6
18. Home 300 yds Bogey 5 18. Rosapenna 300yds Bogey 4
In 3,275 yards Bogey 44 In 3,149 yards Bogey 42
As per reference to a Mr Browne in 1895, I have been advised that it would seem that he made some minor changes, perhaps modifying three green sites, but leaving the bulk of OTM course relatively unchanged. However I have not been able to confirm the extent of Mr Brownes modifications in 1895.