Income Statements - USD ($)	12 Months Ended
	Apr. 30, 2024	Apr. 30, 2023
Income Statement [Abstract]
Net Sales	$ 21,767,000	$ 19,979,000
Less: Cost of Goods Sold	(10,926,000)	(10,605,000)
Gross Profit	10,841,000	9,374,000
Operating Expenses:
General and Administrative	1,492,000	1,380,000
Selling	2,958,000	2,836,000
Engineering	102,000	98,000
Total Operating Expenses	4,552,000	4,314,000
Income From Operations	6,289,000	5,060,000
Other Income (Expense)
Other Income	37,000	6,000
Impairment on Investment in Limited Land Partnership	(38,000)
Dividend and Interest Income	1,116,000	1,068,000
Unrealized Gain (Loss) on Equity Securities	2,771,000	(31,000)
Gain (Loss) on Sale of Investment	148,000	(291,000)
Gain on Sale of Assets		3,000
Total Other Income (Expense)	4,034,000	755,000
Income Before Provisions for Income Taxes	10,323,000	5,815,000
Provisions for Income Taxes
Current Expense	2,115,000	1,226,000
Deferred tax expense (benefit)	650,000	(168,000)
Total Income Tax Expense	2,765,000	1,058,000
Net Income	$ 7,558,000	$ 4,757,000
Earnings Per Share of Common Stock
Basic	$ 1.54	$ 0.96
Diluted	$ 1.53	$ 0.96
Weighted Average Number of Common Shares Outstanding (Basic)	4,913,676	4,930,835
Weighted Average Number of Common Shares Outstanding (Diluted)	4,934,176	4,951,335