[Collins] 75S3 Questions

[Bill Stewart]

I recently received a 75S3 (s/n 12xxx) which was blowing fuses. I found one of the B+ diodes shorted and replaced both with 1N4007 diodes. This rcvr used 1N1084 S/T B+ diodes which fit into a open type fuse holder. The schematic which I have, apparently not for this rcvr, calls for 1N1490 diodes. Also noted is that this rcvr uses 6U8A's instead of the 6EA8's as noted on the schematic I have. Now it's working fine, but I have a few questions.

Question 1: Is there anything special about the B+ diodes. The 1N4007's are working ok and the current rating is well
                  above rcvr requirements. Can the older 1N1084 diodes still be found should I want to return it to orig. config.
Question 2: I am hearing plenty of signals, but the S-meter is very stingy...with only a few sigs going over S-9. Is this 
                  normal S-meter action or could the RF need some tweaking. 
Question 3: Another S-meter question- Should there be enough light from the meter lamp to read the meter in the dark. 
                 Mine has very little light coming around the meter face and is about useless as far as reading it in the dark.
                 Anything special about the meter lamp make up. 
Question 4: The 6BF5 audio tube runs real hot...makes spit sizzle. Is this normal? I'm using a Radio Shack 'scanner'  
                  speaker and am guessing its 8 ohms.
Question 5: Last one for now...the power transformer runs pretty warm...it gets uncomfortable after about 15-20
                  seconds...is this a normal temp.? 

I haven't received a manual yet so I'm operating in the dark a bit. Would this rcvr be toward the end of the plain S3 series being it has a high ser. no. and diode and tube changes. Thanks for any help...73 de Bill K4JYS