I have a Hitachi Projection TV (model 50ux7k) that has some burns in a
couple of the projection tubes from a previous problem on the
deflection board. I am trying to determine if the cost of replacing 2
or all 3 of the tubes would worth the time and money (set is 12 years
old).
I've been checking around for projection tubes and have run into a
question that no one has been able to answer. The service manual for
Hitachi model 50ux7k lists the following part numbers for each tube
assy:

Red - 4866381
Green - 4866382
Blue - 4866383

One source, "Part solver.com", lists these three tubes for $353 each.
They also list these 3 additional part numbers:

Red - 4869321
Green - 4866385
Blue - 4869323

The green is the only one that states it is a replacement for #
4866382 and is listed at $354.
The red and blue are $282 each and do not have any information about
them. I called Customer Service, but they could not tell me any
information about the difference.

Can anyone tell me what the difference is, or lead me to a source that
can clear up the confusion in the following projection tube part
numbers?

Red - 4866381 vs. 4869321
Green - 4866385 vs. 4866385
Blue - 4866383 vs. 4869323

Another source also lists Part # 4866384 as a replacement for the
green projection tube.

Any information to clear up the difference in parts, will be very
helpful in my decision to repair or not to repair.

Thanks,
Joe R.