Hello AT,
Save yourself some money by preping the car if you can. Any assemblies or panels must be removed if in the way. Remove interior trim, carpet seats if possible. The floor pans are welded in place at the factory. The factory floor coverings, sound deadening material, must be removed and the rusty metal must be cut out mechanically or torched or removed with a plasma cutter depending on the available equipment. The surrounding metal must be cleaned of undercoat,rust and paint so the new metal parts can be welded in place again. Afterwards, the welds must be ground, cleaned, primed painted, undercoated etc. If the person doing the work is unfamiliar with the process or the type of car the work will take longer. If this person is working under a jacked up car with welding and cutting sparks falling all over their body, the work will also take longer. Many modern restoration shops have rotating fixtures, so that the car can be positioned to aid in the restorer's speed and quality. The degree of quality specified will make a major difference in price. As original or an undetectable repair will be expensive. Acceptable to industry standards will be less expensive. Avoid a cheap patch for sale. It is the least expensive, but will hurt the value of the car. Many buyers will be on the alert for this kind of work.
Joe Alexander
Blacklick, Ohio