can you send pics of your bending pattern issue. Often it is more technique or the pattern wasn't compensated for the wood that can cause a mismatch.
I agree a iron will help you tweak for irregularities. It is a good skill to have. If you have industrial tooling outlets in your area check out there for heat elements. They are not that expensive.

John,

I'm not the best person to respond, but I'm interested in your question and hopefully you'll get something better than this.
I built a bending machine according to plan but went with light bulbs as the heat source, hoping to avoid the expense of a blanket if I could. Anyway, the machine was not getting hot enough for me, so I thought I would try the bending iron, and I made one similar to that described at the site below, using a 3" outside diameter pipe and a charcoal lighter as the heat source. Didn't really like the idea of an open flame in my garage, so I avoided the propane torch. Anyway the bending iron exceeded my expectations. I think the charcoal ligher was about $12.00 and the dimmer switch was under $10. I actually was able, after some trial and error to get the sides to fit in the mold fairly well; takes a little practice, but you can correct the bend by re-heating. I turn the dimmer switch to about 2/3 power (if you believe the info with the lighter it can get up to 1000F); tried checking temperature with my wife's meat thermometer, but don't think it works too well. Just adjusted so that water droplets sprayed on the iron jumped and vaporized right off. I'm keeping the bending iron, but I did just order a silicon blanket and will be giving the bending machine another go since it looks so lonely sitting on the floor in my garage. Others on the site have mentioned that they use the iron to touch up their sides when they come out of the bending machine. In any case, John, I think you can make an iron pretty cheaply and see how you like it without taking too big a risk. I'm more comfortable with the iron, than I thought I would be.

http://soundsalon.com/Make_a_Bending_Iron.html

I used blankets and forms for many years. I recently switched to a bending iron for my current archtop build, so my only experience so far with the iron is with maple.

My experience with the bending machine is that the blankets often produced excellent results, but sometimes gave me flat spots, uneven curves, and ripples. I occasionally got cracking in cutaways. Invariably, I got more springback than I would have liked.

With the iron, I did several test pieces of maple (mostly flatsawn curly maple), and then I did the "real" pieces (quartersawn and highly flamed). Every piece bent perfectly. No flat spots, the curves were even, and no ripples or cracking. Absolutely no grain lift on the figure. No springback. The only problems I encountered was on (a) on my first test piece, I didn't use enough water and the wood case hardened before I finished the bend, and (b) on one test piece I got very light scorching (so light I hesitate to call it scorching), but it sanded out very quickly and easily.

The cutaway was pretty tight with the iron, and it took a little while to bend the cutaway side (probably 25-30 minutes to get it perfect). I'm sure it will go faster as I get more experience. The non-cutaway side went pretty fast (10 minutes).

With the bending machine, it always takes longer than what it took me to bend with the iron. The bending itself is faster with the bending machine, but setting up the machine, wrapping the sides in foil, and getting the sides perfectly aligned in the bender all takes time. Not to mention the fact that, once you bend, you have to let it sit there a while to cool before you can use the machine again. Also, I have never been thrilled with the results I get from the machine on cutaways, and it is a pain in the neck to sand defects out of the cutaway.

I'll defer final judgment until I have more experience with the iron. Perhaps I will get less favorable results bending sides for flattops (which are wider than archtop sides), or bending species other than maple. But unless I have a radically different experience on future builds, I'll eventually put the bender up for sale.