Hello Colleen,
Sometimes you just have to bite the bullet, mortgage the house, and pay the fees - it all depends on just how badly you want the information. I know because I've had to do it. In the end it was worthwhile though because those Chancery records I got were full of illuminating details.
However, there is a second tack available. Be "Zen" about your search. Imagine that you are that information and think of places that it may also exist.
You mention an Arctic expedition for RACEHORSE. If there is a good reference library accessible to you, spend a day there looking through the indices, bibliographies and footnotes of every book you can find on historical Arctic expeditions. It may be that someone else, years ago, has consulted the very TNA files that you are interested in. Yes, it's a very long shot but sometimes they do pan out.
Cheers,
Westoe
