Equivalent and similar tubes with different bases

This list was expanded from a list here (thanks to Jim Cross!).  The Bold listings are shown as equivalents in a tube manual, and could probably be sustituted without any changes other than rewiring (but check dissipation rating for power tubes!).  The others range from close to somewhat similar... best to compare data sheets before trying.
 
4-5-6-7 Pin Top Cap OCTAL Single-Ended Octal LOKTAL Miniature 7 pin Min. 9 pin Notes
1A4 1D5G         remote cutoff
1A6 1D7G          
1B4, 951 1E5G          
1B5   1H6G        
1C6 1C7G          
1F4   1F5G, 1G5, 1J5        
1F6 1F7G          
19   1J6  3B7 3A5   3A5, 3B7: 1.4 / 2.8V fil.
30   1H4G        
950 1J5G          
    1A5GT, 1Q5, 1C5 1LA4, 1LB4 1S4    
  1A7   1LA6 1L6    
      1LD5 1S5, 1U5    
    1E4G 1LE3, 1LF3 1C3    
  1H5GT   1LH4      
  1N5   1LN5, 1LC5 1L4, 1U4    
  1P5   1LG5 1T4   remote cutoff
    3Q5 3LF4, 3D6, 3LE4 3Q4, 3V4, 3S4    
41   6K6G 7B5 6AR5    
42   6F6G       2A5: 2.5V fil.
43   25A6G        
75 6B6, 6Q7 6SQ7 7B6 6AV6, 6BK6, 6AT6   2A6: 2.5V fil.  mu: 70-100
76   6P5G       56: 2.5V fil 
77, 6C6 6J7G 6SJ7 7C7 6AU6   57: 2.5V fil.
78, 6D6 6K7, 6U7G 6SK7 7A7 6BA6, 6BD6   58: 2.5V fil.  remote cutoff
79   6Y7G        
80   5Y3G, 5Y4G 5AZ4      
83V   5V4G       indirect heating
84/6Z4   6X5 7Y4 6X4 6V4  
    6AX5 7Z4   6CA4, 6BW4  
85 6V7G, 6R7 6SR7, 6SW7 7E6 6BF6, 6CU6   55: 2.5V fil.  mu 16-20
5Z3   5U4G, 5X4G       5BC3 Novar
6A3   6B4G       2A3: 2.5V fil.
807 6BG6 6L6       1619, 1624: 2.5V fil.
6A6   6N7       53: 2.5V fil. 
6A7 6A8G   7B8     2A7: 2.5V fil.
6B5   6N6G        
6B7 6B8G 6SF7 7E7 6CR6   6SF7, 6CR6: 1 diode
    6H6 7A6 6AL5   7A6: 150 mA  fil.
6F7 6P7G          
    6AG7 7AD7   6CL6, 12BY7  
    6AQ7 7K7   6CN7, 6FM8  
    6G6G   6AK6   150 mA filament
    6C5, 6J5, 6L5 7A4, XXL 6C4 12AU7: (6C4 x 2) 6C4, 6L5: 150 mA fil.
    6SA7 7Q7 6BE6    
    6SB7     6BA7 hi transconductance
    6SG7,
6SD7
7H7,
7T7
6HR6   hi transconductance, semi-remote cutoff
    6SE7 7L7      
  6S7 6SS7 7B7 6BJ6   150 mA filament
  6S8       6T8, 6AK8  
  6K5, 6F5 6SF5 7B4 6AQ4   mu=100
    6SL7GT 7F7   5751, 5755 mu=70
      7F8, 14F8   12AT7  
  6F8 6SN7GT,
6AH7
7N7, 7AF7   6CG7, 12BH7 mu=16-20
  6J8   7A8   6AJ8   
  6T7 6SZ7 7C6 6AQ6   150 mA filament
    6V6 7C5 6AQ5, 6HG5 6CM6, 6CZ5, 6061, 6BW6  
    6U6, 6W6 7A5 6AS5, 6BF5 6DS5, 6BK5  
  6W7   7C7 6BH6   150 mA filament
  12A8GT   14B8      
    12A6 14A5     150 mA filament
    12H6   12AL5    
    12SA7 14Q7 12BE6  12BA7  
  12J7 12SJ7 14C7 12AU6    
  12K7 12SK7 14A7 12B7 12BA6, 12BD6    
    12SL7GT 14F7   5751, 5755 mu=70
    12SN7GT, 12AH7 14N7, 14AF7   12BH7, 12FQ7 mu=16-20
      14Y4 12X4 12BW4  
    12V6 14C5 12AQ5 12AB5, 7061  
25B5   25N6G        
    25L6   25C5 25BK5  
25Z5   25Z6G        
    35L6 35A5 35B5, 35C5    
    35Z4GT 35Z3      
    35Z5GT 35Y4 35W4    
    50L6 50A5 50B5, 50C5    
    50Y6 50X6      
    117Z4GT   117Z3    
    2050   2D21    
    7591     6GM5 and 7868 Novar
    6Y6     6GC5, 7754  
    50C6     7965  
    6EM7, 6EA7     6FD7, 6DR7 6GF7 Novar
    6GN7, 6DN7     6DE7, 6EW7