The 7013029 number is what will tell you what it is. According to Holander, it is a 50-62 235 truck carb. Napa/Echlin kit #2-5158 should do the trick.
As to 235 or 261, The important differences are internal, namely pistons, rods and weep holes in the head/block, so unless you are going to tear it completely down, don't worry about it. If it doesn't have the 2 "captain's bars" cast into the block above the starter, its a 235. The blocks are completely different castings, so I doubt that they could have the same casting numbers regardless of reference materials. If someone physically has in their possession one of each with the same casting numbers, then I will believe.
What are the numbers stamped on the block behind the distributor? The letters should tell for sure what it is (US made).
