hiya.....nice to see you care for your gifts but i think you may be worrying too much my friend.....
belt...leave it....i've a merriweather firemns belt here thats 120 years old and its absolutely lovely in the state its in....it hasnt been treated with ANYTHING for decades.
as for the sheath.....i'd say the same really....i've sheaths here i made for myself that have been out with me in every condition and theyve aged beautifully....all i would ever do is give one a wipe over with a dab of fiebings antique medium brown finish then buff it up....as a complete newbie i would say that you trying to mix home made concoctions is not a good idea. a jar of this will last you years:
http://www.ebay.co.uk/itm/FIEBINGS-...UK_Crafts_Leathercraft_LE&hash=item1e73f9f871
if your leatherwork was cracking, rigid stiff, rare/valuable, dry, old, worn i'd give different advice but in my opinion people are dazzled by too much product too many methods and too much hearsay....
really....no offence to anyone but i really dont think you need to do anything to them whatsoever for probably many many years.
regards
s
ps....i would not advise using chemicals on leatherwork unless youve contacted the person who made it. say for instance it had been coated in resolene....much of the above advice would totally mess your leather up. i see the belt is by shark designs....i would advise contacting mark hordon.
pps....sorry, i'm really not trying to upset anyone...but i'd recommend a deeper sheath too....