Hey Pierre,
Glencoe could never be called a "huge" model kit manufacturer, not like Tamiya, Revell-Monogram, Dragon, etc, etc.......
I've read that Glencoe was a small family business that originally made plastic injection dinnerware.
When the company was inherited by a younger family member, the new owner (who was a model builder) decided to buy up some old aircraft model molds from bankrupted manufacturers and/or lease discontinued model molds from other manufacturers.
Hence the weird variety of scales and quality of kits they manufactured and sold.
I bought the Glencoe PT-76 and the BTR-50 APC when they first came out and in a word, they were JUNK!!!
On the other hand, I built their Grumman Duck and SE-5 biplane kits for a friend and quite liked them.
I'm not sure if Glencoe is still around or is still making model kits, you do see the odd kit in the LHS.
Glencoe is/was a minnow compared to some companies like the big T, Hasagawa, R-M, DML et al.
Cheers
jjumbo
update: I just Googled their website, it's "temporarily unavailable"
http://www.glencoe-models.com/