Condensed Consolidated Balance Sheets (Unaudited) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Current Assets
Cash and cash equivalents	$ 1,291,132	$ 1,387,075
Short-term investments	1,374,956	1,771,120
Accounts receivable - Less allowances of $160,000	5,463,717	4,275,882
Contract assets	0	118,301
Inventories, net	6,746,675	7,327,653
Income taxes receivable	534,224	580,287
Other current assets	504,958	380,562
Total current assets	15,915,662	15,840,880
Property, Plant and Equipment
Land and improvements	1,510,513	1,510,513
Buildings and improvements	6,835,619	6,835,619
Production equipment and other	37,724,746	37,952,902
Property, Plant and Equipment, Gross	46,070,878	46,299,034
Less accumulated depreciation	34,695,580	34,633,952
Net property, plant and equipment	11,375,298	11,665,082
Deferred income taxes, net	501,773	324,943
Total assets	27,792,733	27,830,905
Current Liabilities
Accounts payable	1,388,599	788,974
Accrued wages and salaries	634,373	514,900
Other accrued expenses	313,112	129,963
Unearned revenue and customer deposits	284,377	430,179
Total current liabilities	2,620,461	1,864,016
Total liabilities	2,620,461	1,864,016
Shareholders' Equity
Preferred stock, no par value, 500,000 shares authorized: none outstanding	0	0
Common stock, $1.00 par value, 4,000,000 shares authorized, 1,138,096 shares issued; 966,132 shares outstanding	1,138,096	1,138,096
Additional paid-in capital	447,134	447,134
Retained earnings	27,509,140	28,303,757
Treasury stock, 171,964 shares at cost	(3,922,098)	(3,922,098)
Total shareholders' equity	25,172,272	25,966,889
Total liabilities and shareholders' equity	$ 27,792,733	$ 27,830,905