Upgrading root module from 3.7 to latest 4.x

Questions
1

Silverstripe Version: 3.7

Question: Issue upgrading Local module to Silverstripe 4.3

I am trying to upgrade a 3.7 site to latest 4.x version. In the process i managed to upgrade modules defined in composer.json. I also have several local modules at the root level. So there is no composer.json in those modules. I would like to know the following

  1. What is the best process to upgrade them?
  2. I followed the instructions listed here. When i try to run upgrade tool’s inspect command, the process failed with “Class not found exception”. This is the error i get
 Error (Class 'MyOrg\TeacherWeb\SecurePageController' not found) thrown while autoloading class MyOrg\TeacherWeb\SecurePageController.

Also this is the exception trace

Exception trace:
  at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\phpstan\phpstan\src\Broker\Broker.php:229
 PHPStan\Broker\Broker->hasClass() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\phpstan\phpstan\src\Rules\ClassCaseSensitivityCheck.php:27
 PHPStan\Rules\ClassCaseSensitivityCheck->checkClassNames() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\phpstan\phpstan\src\Rules\Namespaces\ExistingNamesInUseRule.php:115
 PHPStan\Rules\Namespaces\ExistingNamesInUseRule->checkClasses() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\phpstan\phpstan\src\Rules\Namespaces\ExistingNamesInUseRule.php:62
 PHPStan\Rules\Namespaces\ExistingNamesInUseRule->processNode() at C:\xampp73\htdocs\silverstripe_upgrade_script\src\UpgradeRule\PHP\Visitor\PHPStanScopeVisitor.php:80
 SilverStripe\Upgrader\UpgradeRule\PHP\Visitor\PHPStanScopeVisitor->SilverStripe\Upgrader\UpgradeRule\PHP\Visitor\{closure}() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\phpstan\ph
pstan\src\Analyser\NodeScopeResolver.php:316
 PHPStan\Analyser\NodeScopeResolver->processNode() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\phpstan\phpstan\src\Analyser\NodeScopeResolver.php:176
 PHPStan\Analyser\NodeScopeResolver->processNodes() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\phpstan\phpstan\src\Analyser\NodeScopeResolver.php:699
 PHPStan\Analyser\NodeScopeResolver->processNode() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\phpstan\phpstan\src\Analyser\NodeScopeResolver.php:176
 PHPStan\Analyser\NodeScopeResolver->processNodes() at C:\xampp73\htdocs\silverstripe_upgrade_script\src\UpgradeRule\PHP\Visitor\PHPStanScopeVisitor.php:82
 SilverStripe\Upgrader\UpgradeRule\PHP\Visitor\PHPStanScopeVisitor->enterNode() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\nikic\php-parser\lib\PhpParser\NodeTraverser.php:159
 PhpParser\NodeTraverser->traverseArray() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\nikic\php-parser\lib\PhpParser\NodeTraverser.php:85
 PhpParser\NodeTraverser->traverse() at C:\xampp73\htdocs\silverstripe_upgrade_script\src\UpgradeRule\PHP\PHPUpgradeRule.php:28
 SilverStripe\Upgrader\UpgradeRule\PHP\PHPUpgradeRule->transformWithVisitors() at C:\xampp73\htdocs\silverstripe_upgrade_script\src\UpgradeRule\PHP\ApiChangeWarningsRule.php:88
 SilverStripe\Upgrader\UpgradeRule\PHP\ApiChangeWarningsRule->mutateSourceWithVisitors() at C:\xampp73\htdocs\silverstripe_upgrade_script\src\UpgradeRule\PHP\ApiChangeWarningsRule.php:60
 SilverStripe\Upgrader\UpgradeRule\PHP\ApiChangeWarningsRule->upgradeFile() at C:\xampp73\htdocs\silverstripe_upgrade_script\src\Upgrader.php:61
 SilverStripe\Upgrader\Upgrader->upgrade() at C:\xampp73\htdocs\silverstripe_upgrade_script\src\Console\InspectCommand.php:88
 SilverStripe\Upgrader\Console\InspectCommand->execute() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\symfony\console\Command\Command.php:255
 Symfony\Component\Console\Command\Command->run() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\symfony\console\Application.php:1000
 Symfony\Component\Console\Application->doRunCommand() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\symfony\console\Application.php:271
 Symfony\Component\Console\Application->doRun() at C:\xampp73\htdocs\silverstripe_upgrade_script\vendor\symfony\console\Application.php:147
 Symfony\Component\Console\Application->run() at C:\xampp73\htdocs\silverstripe_upgrade_script\bin\upgrade-code:55

In mysite/code/model/CustomSubcategoryPageController.php i have the following code

<?php
namespace MyOrg\Web;

use MyOrg\TeacherWeb\SecurePageController;

class CustomSubcategoryPageController extends SecurePageController {

I have SecurePageController in teacher-web\code\controller\SecurePageController.php

My autoload has this code

"autoload": {
        "psr-4": {
            "MyOrg\\Web\\": "mysite/code",
            "MyOrg\\TeacherWeb\\": "teacher-web/code",
            "MyOrg\\Webchat\\": "webchat/code
        }
    }

Can someone please point me in the right direction