Maybe a sporting goods store? They used to sell it. The best thing to put on a new baseball glove.,,,,BD

I've been re-breaking in a vintage Ideale model 60 and after an application of Proofhide and more than a few kilometres of riding what was a dull saddle is starting to shine up very nicely

So far no luck. Tried Charles St in Boston - an area that has a lot of old style stores that aren't preserved
in most parts of the city and not found in a lot of suburbs. Helen's Leather - one spray bottle. Charles St
Supply - keeps all the Brahmin's in supplied with hard goods - 8 different types of leather formulas but no
Neatsfoot. Didn't make it to the shoe repair. Still haven't tried the better supplied bike stores like Wheelworks.

that's hard to believe: here in yuppified SF I can walk to my local Ace hardware and buy Neatsfoot Oil *Compound* in less than 10 minutes. But I wouldn't put that compound on anything I own and care about, it has only a small percentage of real Neatsfoot oil mixed with other oils and mostly petroleum distillates (which can be whatever's cheap). I'd look *online* for PURE Neatsfoot oil unless there's a tack shop for the horsey fox hunting crowd in your neck of Beantown.;)
http://www.amazon.com/Fiebings-Pure-.../dp/B0000B3ASS (just one example online, not an endorsement)

The place you buy shoe polish doesn't have it?

You might also try sporting goods stores. Neatsfoot oil is commonly used on baseball gloves.

I bought some neatsfoot at my local tandy leather factory... Is there one near you? Make sure you get the pure stuff.

http://www.tandyleatherfactory.com/Locations.asp

In my experience, neatsfoot, while a good restorative, gives a only dull sheen, so if you're looking for something shiny similar to a new Brooks and profide isn't doing the trick, then you'll want a finisher. Depending on the condition of the leather you may want any of several products. My suggestion would be to bring the saddle into the shop and ask one of the people there for their opinion...