I don't know about the 1450, but I had the same problem my 1402 which has the same master cylinder set up.
The forward stop is set by a small weldment on the bottom of the stick which contacts the top of the master cylinder (on a 1402). When I replaced my master cylinders, my sticks were no longer lined up due to small differences in the castings. The only way to set them even was to grind off a small amount of metal from the stop on the one furthest back. Then I adjusted the brake actuating levers on the rear end so the sticks came back evenly with full braking applied.
Look at yours and make sure this is what is happening. If the stick is hanging up before it gets to the stop, then the problem lies in the master cylinder. If both sticks are forward to the stops, you can grind off a little from the bottom of the stick stop or the top of the master cylinder of the rearmost stick. A little bit of material removal makes a big difference on the lever position. If you over do it, you can add a little weld to the stop and start over.
If the stick is not all the way forward, the master will not re-prime from the reservoir properly, which could be a problem if you have a small leak in the slave cylinder.
If the stick is not going forward to the stop, the problem lies in the master cylinder itself. Stock 1966 Ford Econoline van master cylinders (used on Imps and Sprytes) have to have some of the casting ground off to clear the forks on the bottom of the lever so it will go fully forward. (In the second picture I installed the cylinders before I realized I had to modify the casting, so out they came) Make sure there is no interference between the stick forks and the casting forward of the pivot. Also look for other things that may be interfering with the stick.
Hope this was helpful and good luck.
Sources for master cylinders
http://www.ebay.com/sch/i.html?_trk...+econoline+master+cylinder&_sacat=0&_from=R40